Cutis

In 2017, consumers spent an average of $8.53 billion on nail services.¹ This booming industry is set to grow to more than $15.5 billion by 2024.² Nail polishes and other nail cosmetic trends can present new exposures for consumers, including chemicals that can elicit allergic contact dermatitis. In this article, we discuss new nail trends and their associated allergens, the acrylates.

Tosylamide/Formaldehyde Resin

Traditionally, the most widely recognized nail polish allergen has been tosylamide/formaldehyde resin (TSFR). However, there now are many touted TSFR-free nail polishes on the market, and the rate of positive reactions to this chemical has been declining in recent years. The North American Contact Dermatitis Group reported a positive reaction rate of 1.3% from 2005 through 2006,³ and rates decreased to 0.9% from 2015 through 2016.⁴ An Australian study demonstrated a similar reduction in positive reaction rates to nail polish chemicals, with only 0.7% of patients reacting to TSFR from 2014 to 2016 and 0% in 2017. It is theorized that this reduction occurred from replacing TSFR in traditional nail polishes with other chemicals such as polyester resins and cellulose acetate butyrate.⁵

Acrylate-Based Nail Treatments

Consumers recently have been gravitating toward acrylate-based nail treatments vs traditional nail polishes for a variety of reasons. Often referred to as gels, dips, or shellac, acrylate-based nail treatments represent a hot new trend in nail cosmetics. These manicures are resistant to chipping and scratches, creating a like-new look that lasts for weeks after application. The long-lasting nature of acrylate-based nail polishes has made them wildly popular with consumers.

Traditional acrylic nails consist of a powder polymer mixed with a liquid monomer, which polymerizes when a catalyst is added.⁶ The procedure is time consuming and can take up to 2 hours for application. In contrast, the newer gel manicure can be completed faster and includes application of acrylate-based nail polish, including a base coat, 2 coats of color, and a top coat. Exposure to either a light-emitting diode (30–60 seconds) or UVA (2 minutes) lamp is necessary after each coat is applied for polymerization (Figure 1).⁶ This long-lasting, semipermanent manicure typically is what patients are referring to when they say they have “gel nails.”

Acrylate Allergy

Patients who are allergic to acrylates can present with different patterns of dermatitis. Although the majority of patients present with dermatitis on the hands, fingers, or wrists, up to 10% may only have facial and neck dermatitis.⁸ Less commonly, the abdomen and thighs can be involved.^6,8 Nail technicians most commonly present with pulpitis with cutaneous fissures.⁸ Other symptoms can include subungual hyperkeratosis, onycholysis, and nail dystrophy. Paresthesia, urticaria, and upper respiratory tract symptoms can occur but are less common.^6,8

Acrylate allergy typically is the result of sensitization to the acrylate monomers. In theory, gel nail acrylate materials are polymerized following exposure to a light-emitting diode or UVA lamp; however, there likely is some incomplete polymerization, which can increase the risk for development of allergy. Allergen exposure can occur due to incorrect application of the light source; inadvertent monomer exposure, which occurs when nail technicians wipe extra acrylate off of a client’s finger(s); or inadvertent application of acrylate monomers to objects in the nail technician’s work environment.^6,8

Several acrylate nail allergens have been reported. Many studies have identified 2-hydroxyethyl methacrylate (HEMA) as the most common nail acrylate allergen.^8,9 At least one study identified 2-hydroxypropyl methacrylate as the most common, with HEMA in second place.⁶ Other reported acrylate allergens have included ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, methyl methacrylate, ethyl cyanoacrylate, 1,4-butanediol diacrylate, hydroxypropyl acrylate, and 2-hydroxyethyl acrylate.^8,9

The American Contact Dermatitis Society Core Allergen Series and the North American Contact Dermatitis Group screening series currently include HEMA, methyl methacrylate, ethyl acrylate, ethyl cyanoacrylate, and TSFR.^4,10 Of note, acrylates are not included in the thin-layer rapid use epicutaneous (T.R.U.E.) patch test (SmartPractice), so they will be missed if this series is used.¹¹ In the setting of suspected nail acrylate allergy, some authors recommend initial screening with HEMA and ethyl cyanoacrylate, with extended acrylate testing if both are negative.⁸

Upon patch testing with an acrylate series, patients frequently react to 2 or more acrylates and the reactions can be strong (++) or extreme (+++), which may represent cosensitization or cross-sensitization.⁸ The likelihood of cross-reactivity between acrylates is not clear, though it has been postulated that it is theoretically possible.⁶

An important pearl for patch testers using the chamber method is proper storage of acrylate allergens and assembly of trays prior to patch testing. Similar to all haptens, manufacturers recommend that acrylates should be stored in a refrigerator, but some authors suggest that acrylates should be stored in the freezer.¹² Acrylates are volatile chemicals and rapidly degrade when exposed to air. A methyl methacrylate preparation loaded into an inert quadrate (IQ) chamber and stored at room temperature showed a nearly undetectable amount of any residual methyl methacrylate 24 hours later. Refrigeration of allergens in chambers slowed but did not stop eventual degradation, with nearly all acrylate preparations reaching an undetectable level of allergen by day 8.¹³ Acrylates, along with other volatile allergens, should only be loaded into chambers immediately prior to placement on the patient.

Allergy Prevention

Prevention of nail acrylate allergy among consumers is simple: avoid contact with the offending allergen. Acrylate spillover (ie, applying the acrylate onto the skin) and direct contact with objects and working surfaces contaminated with acrylate-based nail products should be avoided.⁸ Avoidance is more complicated for nail technicians, but it is thought that nitrile gloves allow for the best dexterity and allergen avoidance when acrylate exposure is brief.¹⁴ Allowable exposure times with nitrile gloves may be 15 to 30 minutes. After this times passes, a glove change is required to avoid exposure.¹⁴ Wearing nitrile gloves for longer than 15 to 30 minutes will result in cutaneous exposure and risk for dermatitis in sensitized patients. If longer wear is desired, one option includes cutting the fingertips off of Silver Shield/4H gloves (Honeywell Safety Products USA, Inc), applying them to the distal fingers, and wearing a standard nitrile glove over top, known as the finger stall technique.⁶ In one study, this technique was recommended to nail technicians with acrylate allergy. A telephone survey conducted 4 to 43 months later confirmed that 36% (8/22) of participants were using the technique without symptoms. In this same study, 73% (16/22) had continued working as nail technicians.⁶

Acrylates are used for other medical purposes, including dental procedures, orthopedic procedures, surgical glues, wound dressings, and contact and intraocular lenses. They also have additional cosmetic applications, including eyelash and hair extensions.⁸ Therefore, it is vital that patients disclose any history of acrylate allergy to both their medical and cosmetic providers.

Our Final Interpretation

Acrylate allergy has become increasingly common, and long-lasting nail treatments often are the culprit. Whether through gels, dips, or shellac, repeated exposure to acrylates through nail treatments can increase the risk for allergy. The T.R.U.E. test alone will not make the diagnosis, as acrylates are not present in this patch test system. It is important to remind your allergic patients that acrylates are present in other compounds used for medical and cosmetic purposes. Avoidance is key, and for allergic patients who love to bedazzle their nails, we suggest less-permanent, acrylate-free nail polishes as alternatives.

In 2017, consumers spent an average of $8.53 billion on nail services.¹ This booming industry is set to grow to more than $15.5 billion by 2024.² Nail polishes and other nail cosmetic trends can present new exposures for consumers, including chemicals that can elicit allergic contact dermatitis. In this article, we discuss new nail trends and their associated allergens, the acrylates.

Tosylamide/Formaldehyde Resin

Traditionally, the most widely recognized nail polish allergen has been tosylamide/formaldehyde resin (TSFR). However, there now are many touted TSFR-free nail polishes on the market, and the rate of positive reactions to this chemical has been declining in recent years. The North American Contact Dermatitis Group reported a positive reaction rate of 1.3% from 2005 through 2006,³ and rates decreased to 0.9% from 2015 through 2016.⁴ An Australian study demonstrated a similar reduction in positive reaction rates to nail polish chemicals, with only 0.7% of patients reacting to TSFR from 2014 to 2016 and 0% in 2017. It is theorized that this reduction occurred from replacing TSFR in traditional nail polishes with other chemicals such as polyester resins and cellulose acetate butyrate.⁵

Acrylate-Based Nail Treatments

Consumers recently have been gravitating toward acrylate-based nail treatments vs traditional nail polishes for a variety of reasons. Often referred to as gels, dips, or shellac, acrylate-based nail treatments represent a hot new trend in nail cosmetics. These manicures are resistant to chipping and scratches, creating a like-new look that lasts for weeks after application. The long-lasting nature of acrylate-based nail polishes has made them wildly popular with consumers.

Traditional acrylic nails consist of a powder polymer mixed with a liquid monomer, which polymerizes when a catalyst is added.⁶ The procedure is time consuming and can take up to 2 hours for application. In contrast, the newer gel manicure can be completed faster and includes application of acrylate-based nail polish, including a base coat, 2 coats of color, and a top coat. Exposure to either a light-emitting diode (30–60 seconds) or UVA (2 minutes) lamp is necessary after each coat is applied for polymerization (Figure 1).⁶ This long-lasting, semipermanent manicure typically is what patients are referring to when they say they have “gel nails.”

Acrylate Allergy

Patients who are allergic to acrylates can present with different patterns of dermatitis. Although the majority of patients present with dermatitis on the hands, fingers, or wrists, up to 10% may only have facial and neck dermatitis.⁸ Less commonly, the abdomen and thighs can be involved.^6,8 Nail technicians most commonly present with pulpitis with cutaneous fissures.⁸ Other symptoms can include subungual hyperkeratosis, onycholysis, and nail dystrophy. Paresthesia, urticaria, and upper respiratory tract symptoms can occur but are less common.^6,8

Acrylate allergy typically is the result of sensitization to the acrylate monomers. In theory, gel nail acrylate materials are polymerized following exposure to a light-emitting diode or UVA lamp; however, there likely is some incomplete polymerization, which can increase the risk for development of allergy. Allergen exposure can occur due to incorrect application of the light source; inadvertent monomer exposure, which occurs when nail technicians wipe extra acrylate off of a client’s finger(s); or inadvertent application of acrylate monomers to objects in the nail technician’s work environment.^6,8

Several acrylate nail allergens have been reported. Many studies have identified 2-hydroxyethyl methacrylate (HEMA) as the most common nail acrylate allergen.^8,9 At least one study identified 2-hydroxypropyl methacrylate as the most common, with HEMA in second place.⁶ Other reported acrylate allergens have included ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, methyl methacrylate, ethyl cyanoacrylate, 1,4-butanediol diacrylate, hydroxypropyl acrylate, and 2-hydroxyethyl acrylate.^8,9

The American Contact Dermatitis Society Core Allergen Series and the North American Contact Dermatitis Group screening series currently include HEMA, methyl methacrylate, ethyl acrylate, ethyl cyanoacrylate, and TSFR.^4,10 Of note, acrylates are not included in the thin-layer rapid use epicutaneous (T.R.U.E.) patch test (SmartPractice), so they will be missed if this series is used.¹¹ In the setting of suspected nail acrylate allergy, some authors recommend initial screening with HEMA and ethyl cyanoacrylate, with extended acrylate testing if both are negative.⁸

Upon patch testing with an acrylate series, patients frequently react to 2 or more acrylates and the reactions can be strong (++) or extreme (+++), which may represent cosensitization or cross-sensitization.⁸ The likelihood of cross-reactivity between acrylates is not clear, though it has been postulated that it is theoretically possible.⁶

An important pearl for patch testers using the chamber method is proper storage of acrylate allergens and assembly of trays prior to patch testing. Similar to all haptens, manufacturers recommend that acrylates should be stored in a refrigerator, but some authors suggest that acrylates should be stored in the freezer.¹² Acrylates are volatile chemicals and rapidly degrade when exposed to air. A methyl methacrylate preparation loaded into an inert quadrate (IQ) chamber and stored at room temperature showed a nearly undetectable amount of any residual methyl methacrylate 24 hours later. Refrigeration of allergens in chambers slowed but did not stop eventual degradation, with nearly all acrylate preparations reaching an undetectable level of allergen by day 8.¹³ Acrylates, along with other volatile allergens, should only be loaded into chambers immediately prior to placement on the patient.

Allergy Prevention

Prevention of nail acrylate allergy among consumers is simple: avoid contact with the offending allergen. Acrylate spillover (ie, applying the acrylate onto the skin) and direct contact with objects and working surfaces contaminated with acrylate-based nail products should be avoided.⁸ Avoidance is more complicated for nail technicians, but it is thought that nitrile gloves allow for the best dexterity and allergen avoidance when acrylate exposure is brief.¹⁴ Allowable exposure times with nitrile gloves may be 15 to 30 minutes. After this times passes, a glove change is required to avoid exposure.¹⁴ Wearing nitrile gloves for longer than 15 to 30 minutes will result in cutaneous exposure and risk for dermatitis in sensitized patients. If longer wear is desired, one option includes cutting the fingertips off of Silver Shield/4H gloves (Honeywell Safety Products USA, Inc), applying them to the distal fingers, and wearing a standard nitrile glove over top, known as the finger stall technique.⁶ In one study, this technique was recommended to nail technicians with acrylate allergy. A telephone survey conducted 4 to 43 months later confirmed that 36% (8/22) of participants were using the technique without symptoms. In this same study, 73% (16/22) had continued working as nail technicians.⁶

Acrylates are used for other medical purposes, including dental procedures, orthopedic procedures, surgical glues, wound dressings, and contact and intraocular lenses. They also have additional cosmetic applications, including eyelash and hair extensions.⁸ Therefore, it is vital that patients disclose any history of acrylate allergy to both their medical and cosmetic providers.

Our Final Interpretation

Acrylate allergy has become increasingly common, and long-lasting nail treatments often are the culprit. Whether through gels, dips, or shellac, repeated exposure to acrylates through nail treatments can increase the risk for allergy. The T.R.U.E. test alone will not make the diagnosis, as acrylates are not present in this patch test system. It is important to remind your allergic patients that acrylates are present in other compounds used for medical and cosmetic purposes. Avoidance is key, and for allergic patients who love to bedazzle their nails, we suggest less-permanent, acrylate-free nail polishes as alternatives.

In 2017, consumers spent an average of $8.53 billion on nail services.¹ This booming industry is set to grow to more than $15.5 billion by 2024.² Nail polishes and other nail cosmetic trends can present new exposures for consumers, including chemicals that can elicit allergic contact dermatitis. In this article, we discuss new nail trends and their associated allergens, the acrylates.

Tosylamide/Formaldehyde Resin

Traditionally, the most widely recognized nail polish allergen has been tosylamide/formaldehyde resin (TSFR). However, there now are many touted TSFR-free nail polishes on the market, and the rate of positive reactions to this chemical has been declining in recent years. The North American Contact Dermatitis Group reported a positive reaction rate of 1.3% from 2005 through 2006,³ and rates decreased to 0.9% from 2015 through 2016.⁴ An Australian study demonstrated a similar reduction in positive reaction rates to nail polish chemicals, with only 0.7% of patients reacting to TSFR from 2014 to 2016 and 0% in 2017. It is theorized that this reduction occurred from replacing TSFR in traditional nail polishes with other chemicals such as polyester resins and cellulose acetate butyrate.⁵

Acrylate-Based Nail Treatments

Consumers recently have been gravitating toward acrylate-based nail treatments vs traditional nail polishes for a variety of reasons. Often referred to as gels, dips, or shellac, acrylate-based nail treatments represent a hot new trend in nail cosmetics. These manicures are resistant to chipping and scratches, creating a like-new look that lasts for weeks after application. The long-lasting nature of acrylate-based nail polishes has made them wildly popular with consumers.

Traditional acrylic nails consist of a powder polymer mixed with a liquid monomer, which polymerizes when a catalyst is added.⁶ The procedure is time consuming and can take up to 2 hours for application. In contrast, the newer gel manicure can be completed faster and includes application of acrylate-based nail polish, including a base coat, 2 coats of color, and a top coat. Exposure to either a light-emitting diode (30–60 seconds) or UVA (2 minutes) lamp is necessary after each coat is applied for polymerization (Figure 1).⁶ This long-lasting, semipermanent manicure typically is what patients are referring to when they say they have “gel nails.”

Acrylate Allergy

Patients who are allergic to acrylates can present with different patterns of dermatitis. Although the majority of patients present with dermatitis on the hands, fingers, or wrists, up to 10% may only have facial and neck dermatitis.⁸ Less commonly, the abdomen and thighs can be involved.^6,8 Nail technicians most commonly present with pulpitis with cutaneous fissures.⁸ Other symptoms can include subungual hyperkeratosis, onycholysis, and nail dystrophy. Paresthesia, urticaria, and upper respiratory tract symptoms can occur but are less common.^6,8

Acrylate allergy typically is the result of sensitization to the acrylate monomers. In theory, gel nail acrylate materials are polymerized following exposure to a light-emitting diode or UVA lamp; however, there likely is some incomplete polymerization, which can increase the risk for development of allergy. Allergen exposure can occur due to incorrect application of the light source; inadvertent monomer exposure, which occurs when nail technicians wipe extra acrylate off of a client’s finger(s); or inadvertent application of acrylate monomers to objects in the nail technician’s work environment.^6,8

Several acrylate nail allergens have been reported. Many studies have identified 2-hydroxyethyl methacrylate (HEMA) as the most common nail acrylate allergen.^8,9 At least one study identified 2-hydroxypropyl methacrylate as the most common, with HEMA in second place.⁶ Other reported acrylate allergens have included ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, methyl methacrylate, ethyl cyanoacrylate, 1,4-butanediol diacrylate, hydroxypropyl acrylate, and 2-hydroxyethyl acrylate.^8,9

The American Contact Dermatitis Society Core Allergen Series and the North American Contact Dermatitis Group screening series currently include HEMA, methyl methacrylate, ethyl acrylate, ethyl cyanoacrylate, and TSFR.^4,10 Of note, acrylates are not included in the thin-layer rapid use epicutaneous (T.R.U.E.) patch test (SmartPractice), so they will be missed if this series is used.¹¹ In the setting of suspected nail acrylate allergy, some authors recommend initial screening with HEMA and ethyl cyanoacrylate, with extended acrylate testing if both are negative.⁸

Upon patch testing with an acrylate series, patients frequently react to 2 or more acrylates and the reactions can be strong (++) or extreme (+++), which may represent cosensitization or cross-sensitization.⁸ The likelihood of cross-reactivity between acrylates is not clear, though it has been postulated that it is theoretically possible.⁶

An important pearl for patch testers using the chamber method is proper storage of acrylate allergens and assembly of trays prior to patch testing. Similar to all haptens, manufacturers recommend that acrylates should be stored in a refrigerator, but some authors suggest that acrylates should be stored in the freezer.¹² Acrylates are volatile chemicals and rapidly degrade when exposed to air. A methyl methacrylate preparation loaded into an inert quadrate (IQ) chamber and stored at room temperature showed a nearly undetectable amount of any residual methyl methacrylate 24 hours later. Refrigeration of allergens in chambers slowed but did not stop eventual degradation, with nearly all acrylate preparations reaching an undetectable level of allergen by day 8.¹³ Acrylates, along with other volatile allergens, should only be loaded into chambers immediately prior to placement on the patient.

Allergy Prevention

Prevention of nail acrylate allergy among consumers is simple: avoid contact with the offending allergen. Acrylate spillover (ie, applying the acrylate onto the skin) and direct contact with objects and working surfaces contaminated with acrylate-based nail products should be avoided.⁸ Avoidance is more complicated for nail technicians, but it is thought that nitrile gloves allow for the best dexterity and allergen avoidance when acrylate exposure is brief.¹⁴ Allowable exposure times with nitrile gloves may be 15 to 30 minutes. After this times passes, a glove change is required to avoid exposure.¹⁴ Wearing nitrile gloves for longer than 15 to 30 minutes will result in cutaneous exposure and risk for dermatitis in sensitized patients. If longer wear is desired, one option includes cutting the fingertips off of Silver Shield/4H gloves (Honeywell Safety Products USA, Inc), applying them to the distal fingers, and wearing a standard nitrile glove over top, known as the finger stall technique.⁶ In one study, this technique was recommended to nail technicians with acrylate allergy. A telephone survey conducted 4 to 43 months later confirmed that 36% (8/22) of participants were using the technique without symptoms. In this same study, 73% (16/22) had continued working as nail technicians.⁶

Acrylates are used for other medical purposes, including dental procedures, orthopedic procedures, surgical glues, wound dressings, and contact and intraocular lenses. They also have additional cosmetic applications, including eyelash and hair extensions.⁸ Therefore, it is vital that patients disclose any history of acrylate allergy to both their medical and cosmetic providers.

Our Final Interpretation

Acrylate allergy has become increasingly common, and long-lasting nail treatments often are the culprit. Whether through gels, dips, or shellac, repeated exposure to acrylates through nail treatments can increase the risk for allergy. The T.R.U.E. test alone will not make the diagnosis, as acrylates are not present in this patch test system. It is important to remind your allergic patients that acrylates are present in other compounds used for medical and cosmetic purposes. Avoidance is key, and for allergic patients who love to bedazzle their nails, we suggest less-permanent, acrylate-free nail polishes as alternatives.

To the Editor:

A 17-year-old adolescent girl presented to the dermatology clinic with a tender pruritic rash on the left wrist that was spreading to the bilateral arms and legs of several years’ duration. An area of a prior biopsy on the left wrist was healing well with use of petroleum jelly and halcinonide cream. The patient denied any constitutional symptoms.

Physical examination revealed numerous erythematous papules coalescing into plaques on the bilateral anterior and posterior arms and legs, including some erythematous macules and papules on the palms and soles. The original area of involvement on the left dorsal medial wrist demonstrated a background of erythema with overlying peripheral scaling and resolving violaceous to erythematous papules with signs of serosanguineous crusting (Figure 1). Scattered perifollicular erythema was present on the posterior aspects of the bilateral thighs and arms (Figure 2). Baseline complete blood cell count and complete metabolic panel were within reference range.

To the Editor:

A 17-year-old adolescent girl presented to the dermatology clinic with a tender pruritic rash on the left wrist that was spreading to the bilateral arms and legs of several years’ duration. An area of a prior biopsy on the left wrist was healing well with use of petroleum jelly and halcinonide cream. The patient denied any constitutional symptoms.

Physical examination revealed numerous erythematous papules coalescing into plaques on the bilateral anterior and posterior arms and legs, including some erythematous macules and papules on the palms and soles. The original area of involvement on the left dorsal medial wrist demonstrated a background of erythema with overlying peripheral scaling and resolving violaceous to erythematous papules with signs of serosanguineous crusting (Figure 1). Scattered perifollicular erythema was present on the posterior aspects of the bilateral thighs and arms (Figure 2). Baseline complete blood cell count and complete metabolic panel were within reference range.

To the Editor:

A 17-year-old adolescent girl presented to the dermatology clinic with a tender pruritic rash on the left wrist that was spreading to the bilateral arms and legs of several years’ duration. An area of a prior biopsy on the left wrist was healing well with use of petroleum jelly and halcinonide cream. The patient denied any constitutional symptoms.

Physical examination revealed numerous erythematous papules coalescing into plaques on the bilateral anterior and posterior arms and legs, including some erythematous macules and papules on the palms and soles. The original area of involvement on the left dorsal medial wrist demonstrated a background of erythema with overlying peripheral scaling and resolving violaceous to erythematous papules with signs of serosanguineous crusting (Figure 1). Scattered perifollicular erythema was present on the posterior aspects of the bilateral thighs and arms (Figure 2). Baseline complete blood cell count and complete metabolic panel were within reference range.

To the Editor:

Solid-organ transplant recipients can develop a range of dermatologic consequences due to chronic immunosuppression, including frequent skin infections and malignancies. Atopic dermatitis (AD) and psoriasis are relatively rare in this population because many immunosuppressive therapies, such as mycophenolate mofetil and tacrolimus, also are used to treat inflammatory dermatoses.¹ In a large renal transplant population, the prevalence of AD was 1.3%.² The pathogenesis of posttransplantation AD is poorly understood, and standard treatment regimens have not been defined. Dupilumab is a novel biologic medication that has demonstrated efficacy in the treatment of AD.³ Reports of dupilumab use for AD management in solid-organ transplant recipients are limited in the literature.

A 29-year-old woman with a history of a heart transplant 4 years prior presented to our dermatology clinic with an itchy rash over the entire body. Since the transplant, she had been on long-term immunosuppression with prednisone, mycophenolate mofetil, and tacrolimus. The rash appeared after she switched from brand-name to generic versions of the medications. Physical examination revealed erythematous scaly plaques on the lateral face, back, chest, arms, and legs covering approximately 10% of the body surface area. The patient’s total serum IgE level was elevated at 711,500 µg/L (reference range, 0–1500 µg/L). Outside biopsies revealed changes consistent with spongiotic dermatitis, and patch testing performed by an outside physician was positive for sensitivity to the preservative bronopol.

The patient was switched back to brand-name tacrolimus, but the rash did not improve. Topical steroids, phototherapy, and omalizumab were ineffective. The itching was primarily managed with desoximetasone spray, mometasone cream, and loratidine. With approval from the patient’s transplant team outside of our hospital system, she was started on dupilumab 300 mg once every 14 days. Complete clearance of the rash was noted within 3 months of treatment. Besides bilateral conjunctivitis, which was treated with ophthalmic prednisolone and moxifloxacin solutions, dupilumab was well tolerated. No issues related to immunosuppressant levels or graft-related issues, including rejection, were reported at 6-, 12-, and 18-month follow-up visits.

Atopic dermatitis is characterized by activation of type 2 immune responses, skin barrier defects, and increased Staphylococcus aureus colonization.⁴ A potential mechanism for the development of AD in transplant recipients relates to their use of tacrolimus for chronic immunosuppression. Tacrolimus increases intestinal permeability and therefore allows greater absorption of allergens. This influx of allergens promotes hypersensitivity reactions, resulting in elevated IgE levels and eosinophilia. Tacrolimus also facilitates predominance of helper T cells (T_H2 cytokines) through selective inhibition of the T_H1 cytokine IL-2.⁵

Dupilumab is a human monoclonal antibody that blocks IL-4 and IL-13, which are key drivers of T_H2-mediated inflammation. In addition to downregulation of inflammatory mediators, dupilumab also increases production of epidermal barrier proteins, resulting in skin repair. It has demonstrated rapid, dose-dependent efficacy in patients with moderate to severe AD.⁶ Dupilumab boasts a good safety profile with no increase in risk for skin infections compared to placebo⁶; however, its safety has not yet been verified in transplant recipients.

Our case is notable for the severity of the patient’s AD despite considerable immunosuppression with transplant medications. Development of AD was associated with a switch from brand-name to generic drugs, which is not commonly reported. Her condition was refractory to a litany of treatments prior to a trial of dupilumab. The rapid clearance observed with this novel biologic medication highlights its potential to provide relief to patients who have particularly tenacious cases of AD. Prior to starting dupilumab, we do recommend more extensive laboratory testing in immunosuppressed patients including transplant recipients and patients with human immunodeficiency virus. We illustrate that a history of solid-organ transplant need not exclude patients from consideration for dupilumab therapy.

To the Editor:

Solid-organ transplant recipients can develop a range of dermatologic consequences due to chronic immunosuppression, including frequent skin infections and malignancies. Atopic dermatitis (AD) and psoriasis are relatively rare in this population because many immunosuppressive therapies, such as mycophenolate mofetil and tacrolimus, also are used to treat inflammatory dermatoses.¹ In a large renal transplant population, the prevalence of AD was 1.3%.² The pathogenesis of posttransplantation AD is poorly understood, and standard treatment regimens have not been defined. Dupilumab is a novel biologic medication that has demonstrated efficacy in the treatment of AD.³ Reports of dupilumab use for AD management in solid-organ transplant recipients are limited in the literature.

A 29-year-old woman with a history of a heart transplant 4 years prior presented to our dermatology clinic with an itchy rash over the entire body. Since the transplant, she had been on long-term immunosuppression with prednisone, mycophenolate mofetil, and tacrolimus. The rash appeared after she switched from brand-name to generic versions of the medications. Physical examination revealed erythematous scaly plaques on the lateral face, back, chest, arms, and legs covering approximately 10% of the body surface area. The patient’s total serum IgE level was elevated at 711,500 µg/L (reference range, 0–1500 µg/L). Outside biopsies revealed changes consistent with spongiotic dermatitis, and patch testing performed by an outside physician was positive for sensitivity to the preservative bronopol.

The patient was switched back to brand-name tacrolimus, but the rash did not improve. Topical steroids, phototherapy, and omalizumab were ineffective. The itching was primarily managed with desoximetasone spray, mometasone cream, and loratidine. With approval from the patient’s transplant team outside of our hospital system, she was started on dupilumab 300 mg once every 14 days. Complete clearance of the rash was noted within 3 months of treatment. Besides bilateral conjunctivitis, which was treated with ophthalmic prednisolone and moxifloxacin solutions, dupilumab was well tolerated. No issues related to immunosuppressant levels or graft-related issues, including rejection, were reported at 6-, 12-, and 18-month follow-up visits.

Atopic dermatitis is characterized by activation of type 2 immune responses, skin barrier defects, and increased Staphylococcus aureus colonization.⁴ A potential mechanism for the development of AD in transplant recipients relates to their use of tacrolimus for chronic immunosuppression. Tacrolimus increases intestinal permeability and therefore allows greater absorption of allergens. This influx of allergens promotes hypersensitivity reactions, resulting in elevated IgE levels and eosinophilia. Tacrolimus also facilitates predominance of helper T cells (T_H2 cytokines) through selective inhibition of the T_H1 cytokine IL-2.⁵

Dupilumab is a human monoclonal antibody that blocks IL-4 and IL-13, which are key drivers of T_H2-mediated inflammation. In addition to downregulation of inflammatory mediators, dupilumab also increases production of epidermal barrier proteins, resulting in skin repair. It has demonstrated rapid, dose-dependent efficacy in patients with moderate to severe AD.⁶ Dupilumab boasts a good safety profile with no increase in risk for skin infections compared to placebo⁶; however, its safety has not yet been verified in transplant recipients.

Our case is notable for the severity of the patient’s AD despite considerable immunosuppression with transplant medications. Development of AD was associated with a switch from brand-name to generic drugs, which is not commonly reported. Her condition was refractory to a litany of treatments prior to a trial of dupilumab. The rapid clearance observed with this novel biologic medication highlights its potential to provide relief to patients who have particularly tenacious cases of AD. Prior to starting dupilumab, we do recommend more extensive laboratory testing in immunosuppressed patients including transplant recipients and patients with human immunodeficiency virus. We illustrate that a history of solid-organ transplant need not exclude patients from consideration for dupilumab therapy.

To the Editor:

Solid-organ transplant recipients can develop a range of dermatologic consequences due to chronic immunosuppression, including frequent skin infections and malignancies. Atopic dermatitis (AD) and psoriasis are relatively rare in this population because many immunosuppressive therapies, such as mycophenolate mofetil and tacrolimus, also are used to treat inflammatory dermatoses.¹ In a large renal transplant population, the prevalence of AD was 1.3%.² The pathogenesis of posttransplantation AD is poorly understood, and standard treatment regimens have not been defined. Dupilumab is a novel biologic medication that has demonstrated efficacy in the treatment of AD.³ Reports of dupilumab use for AD management in solid-organ transplant recipients are limited in the literature.

A 29-year-old woman with a history of a heart transplant 4 years prior presented to our dermatology clinic with an itchy rash over the entire body. Since the transplant, she had been on long-term immunosuppression with prednisone, mycophenolate mofetil, and tacrolimus. The rash appeared after she switched from brand-name to generic versions of the medications. Physical examination revealed erythematous scaly plaques on the lateral face, back, chest, arms, and legs covering approximately 10% of the body surface area. The patient’s total serum IgE level was elevated at 711,500 µg/L (reference range, 0–1500 µg/L). Outside biopsies revealed changes consistent with spongiotic dermatitis, and patch testing performed by an outside physician was positive for sensitivity to the preservative bronopol.

The patient was switched back to brand-name tacrolimus, but the rash did not improve. Topical steroids, phototherapy, and omalizumab were ineffective. The itching was primarily managed with desoximetasone spray, mometasone cream, and loratidine. With approval from the patient’s transplant team outside of our hospital system, she was started on dupilumab 300 mg once every 14 days. Complete clearance of the rash was noted within 3 months of treatment. Besides bilateral conjunctivitis, which was treated with ophthalmic prednisolone and moxifloxacin solutions, dupilumab was well tolerated. No issues related to immunosuppressant levels or graft-related issues, including rejection, were reported at 6-, 12-, and 18-month follow-up visits.

Atopic dermatitis is characterized by activation of type 2 immune responses, skin barrier defects, and increased Staphylococcus aureus colonization.⁴ A potential mechanism for the development of AD in transplant recipients relates to their use of tacrolimus for chronic immunosuppression. Tacrolimus increases intestinal permeability and therefore allows greater absorption of allergens. This influx of allergens promotes hypersensitivity reactions, resulting in elevated IgE levels and eosinophilia. Tacrolimus also facilitates predominance of helper T cells (T_H2 cytokines) through selective inhibition of the T_H1 cytokine IL-2.⁵

Dupilumab is a human monoclonal antibody that blocks IL-4 and IL-13, which are key drivers of T_H2-mediated inflammation. In addition to downregulation of inflammatory mediators, dupilumab also increases production of epidermal barrier proteins, resulting in skin repair. It has demonstrated rapid, dose-dependent efficacy in patients with moderate to severe AD.⁶ Dupilumab boasts a good safety profile with no increase in risk for skin infections compared to placebo⁶; however, its safety has not yet been verified in transplant recipients.

Our case is notable for the severity of the patient’s AD despite considerable immunosuppression with transplant medications. Development of AD was associated with a switch from brand-name to generic drugs, which is not commonly reported. Her condition was refractory to a litany of treatments prior to a trial of dupilumab. The rapid clearance observed with this novel biologic medication highlights its potential to provide relief to patients who have particularly tenacious cases of AD. Prior to starting dupilumab, we do recommend more extensive laboratory testing in immunosuppressed patients including transplant recipients and patients with human immunodeficiency virus. We illustrate that a history of solid-organ transplant need not exclude patients from consideration for dupilumab therapy.

The Diagnosis: Vestibular Papillomatosis  

Vestibular papillomatosis (VP), the female equivalent of pearly penile papules, is characterized by multiple papules in a linear array on the labia minora and is considered a normal anatomic variant. It typically presents as monomorphous, soft, flesh-colored, filiform papules that are distributed in a symmetric fashion. In women, the papules present as linear arrays on the inner aspects of the labia minora, whereas in men, they present in a circumferential array along the sulcus of the glans penis.¹ Lesions often are asymptomatic but may cause itching, burning, and dyspareunia.² Previously believed to be associated with human papillomavirus infection,³ VP is now considered a noninfectious condition. Biopsy reveals parakeratosis and perinuclear vacuolization in the absence of true koilocytes.^4,5 Dermoscopy and reflectance confocal microscopy have been used to differentiate VP from clinically similar lesions (eg, condyloma acuminatum).^6,7 The prevalence of this condition is not well established; however, one study found VP in 1% of women attending genitourinary medicine clinics.³ 

Condyloma acuminatum, known colloquially as genital warts, is a human papillomavirus infection. Lesions tend to be painless and firm and are distributed asymmetrically with a cauliflowerlike appearance.¹ Condyloma latum, found in secondary syphilis, is characterized by papules that are pale, smooth, flat topped, and moist.⁸ Molluscum contagiosum is an infection caused by a poxvirus presenting with flesh-colored, dome-shaped papules with central umbilication.⁹ The lesions of papulosquamous lichen planus are violaceous polygonal papules that affect the clitoral hood and labia minora and may cause pruritus. The cause of lichen planus is unknown; however, clinically similar lesions may occur in a lichenoid drug eruption due to certain medications. 

Vestibular papillomatosis typically does not require treatment, except in symptomatic cases. To date, limited studies have reported variable treatment success utilizing destructive techniques such as CO2 laser or topical application of 5-fluorouracil or trichloroacetic acid.¹⁰  

The lesions on our patient's left medial labia minora were successfully treated with low-voltage (3.0 V) electrodesiccation. Following local anesthesia with 1% lidocaine, each papule was gently electrodesiccated utilizing a standard hyfrecation electrode tip to a light gray discoloration. Postprocedural care involved only twice-daily cleansing with a gentle soap and application of petrolatum. The patient tolerated the procedure well and was satisfied with the cosmetic and functional results. She subsequently underwent treatment of the lesions on the right labia minora with equivalent treatment success.  
 

The Diagnosis: Vestibular Papillomatosis  

Vestibular papillomatosis (VP), the female equivalent of pearly penile papules, is characterized by multiple papules in a linear array on the labia minora and is considered a normal anatomic variant. It typically presents as monomorphous, soft, flesh-colored, filiform papules that are distributed in a symmetric fashion. In women, the papules present as linear arrays on the inner aspects of the labia minora, whereas in men, they present in a circumferential array along the sulcus of the glans penis.¹ Lesions often are asymptomatic but may cause itching, burning, and dyspareunia.² Previously believed to be associated with human papillomavirus infection,³ VP is now considered a noninfectious condition. Biopsy reveals parakeratosis and perinuclear vacuolization in the absence of true koilocytes.^4,5 Dermoscopy and reflectance confocal microscopy have been used to differentiate VP from clinically similar lesions (eg, condyloma acuminatum).^6,7 The prevalence of this condition is not well established; however, one study found VP in 1% of women attending genitourinary medicine clinics.³ 

Condyloma acuminatum, known colloquially as genital warts, is a human papillomavirus infection. Lesions tend to be painless and firm and are distributed asymmetrically with a cauliflowerlike appearance.¹ Condyloma latum, found in secondary syphilis, is characterized by papules that are pale, smooth, flat topped, and moist.⁸ Molluscum contagiosum is an infection caused by a poxvirus presenting with flesh-colored, dome-shaped papules with central umbilication.⁹ The lesions of papulosquamous lichen planus are violaceous polygonal papules that affect the clitoral hood and labia minora and may cause pruritus. The cause of lichen planus is unknown; however, clinically similar lesions may occur in a lichenoid drug eruption due to certain medications. 

Vestibular papillomatosis typically does not require treatment, except in symptomatic cases. To date, limited studies have reported variable treatment success utilizing destructive techniques such as CO2 laser or topical application of 5-fluorouracil or trichloroacetic acid.¹⁰  

The lesions on our patient's left medial labia minora were successfully treated with low-voltage (3.0 V) electrodesiccation. Following local anesthesia with 1% lidocaine, each papule was gently electrodesiccated utilizing a standard hyfrecation electrode tip to a light gray discoloration. Postprocedural care involved only twice-daily cleansing with a gentle soap and application of petrolatum. The patient tolerated the procedure well and was satisfied with the cosmetic and functional results. She subsequently underwent treatment of the lesions on the right labia minora with equivalent treatment success.  
 

The Diagnosis: Vestibular Papillomatosis  

Vestibular papillomatosis (VP), the female equivalent of pearly penile papules, is characterized by multiple papules in a linear array on the labia minora and is considered a normal anatomic variant. It typically presents as monomorphous, soft, flesh-colored, filiform papules that are distributed in a symmetric fashion. In women, the papules present as linear arrays on the inner aspects of the labia minora, whereas in men, they present in a circumferential array along the sulcus of the glans penis.¹ Lesions often are asymptomatic but may cause itching, burning, and dyspareunia.² Previously believed to be associated with human papillomavirus infection,³ VP is now considered a noninfectious condition. Biopsy reveals parakeratosis and perinuclear vacuolization in the absence of true koilocytes.^4,5 Dermoscopy and reflectance confocal microscopy have been used to differentiate VP from clinically similar lesions (eg, condyloma acuminatum).^6,7 The prevalence of this condition is not well established; however, one study found VP in 1% of women attending genitourinary medicine clinics.³ 

Condyloma acuminatum, known colloquially as genital warts, is a human papillomavirus infection. Lesions tend to be painless and firm and are distributed asymmetrically with a cauliflowerlike appearance.¹ Condyloma latum, found in secondary syphilis, is characterized by papules that are pale, smooth, flat topped, and moist.⁸ Molluscum contagiosum is an infection caused by a poxvirus presenting with flesh-colored, dome-shaped papules with central umbilication.⁹ The lesions of papulosquamous lichen planus are violaceous polygonal papules that affect the clitoral hood and labia minora and may cause pruritus. The cause of lichen planus is unknown; however, clinically similar lesions may occur in a lichenoid drug eruption due to certain medications. 

Vestibular papillomatosis typically does not require treatment, except in symptomatic cases. To date, limited studies have reported variable treatment success utilizing destructive techniques such as CO2 laser or topical application of 5-fluorouracil or trichloroacetic acid.¹⁰  

The lesions on our patient's left medial labia minora were successfully treated with low-voltage (3.0 V) electrodesiccation. Following local anesthesia with 1% lidocaine, each papule was gently electrodesiccated utilizing a standard hyfrecation electrode tip to a light gray discoloration. Postprocedural care involved only twice-daily cleansing with a gentle soap and application of petrolatum. The patient tolerated the procedure well and was satisfied with the cosmetic and functional results. She subsequently underwent treatment of the lesions on the right labia minora with equivalent treatment success.  
 

To the Editor:

A 68-year-old white man presented with a firm, gradually enlarging, mildly tender, grayish black papule with central ulceration on the left dorsal wrist of 4 months’ duration (Figure 1). His relevant medical history included multiple basal cell carcinomas (BCCs) and squamous cell carcinomas, as well as a single-lung transplant 2 years prior, for which he was on chronic immunosuppressive therapy with azathioprine, everolimus, tacrolimus, and prednisone. The clinical differential diagnosis included pigmented BCC, malignant melanoma, and ulcerated squamous cell carcinoma.

Histologic examination of the lesion (Figure 2) demonstrated irregular nodules of basaloid tumor cells with rounded nuclei, visible nucleoli, and scant cytoplasm involving the dermis. The tumor produced abrupt matrical-type keratinization, forming ghost cells. The lesion also contained frequent mitotic figures, apoptotic cells, focal areas of necrosis, and abundant melanin pigment. Admixed throughout the lesion were pigmented and dendritic melanocytic cells. The overlying epidermis was focally ulcerated with an adjacent localized connection between the tumor and the epidermis. Keratinocyte atypia was found in the surrounding epidermis, which contained melanophages, solar elastosis, and scattered chronic inflammatory cells. An immunohistochemical study (Figure 3) for tyrosinase demonstrated abundant admixed melanocytic cells. β-Catenin expression was shown in both nuclear and cytoplasmic distributions, and there was focal labeling on BerEP4 staining. Based on these findings, a diagnosis of melanocytic matrical carcinoma (MMC) was made.

Melanocytic matricoma (MM), a rare adnexal tumor, was first described in 1999 by Carlson et al.¹ A PubMed search of articles indexed for MEDLINE using the terms melanocytic and matricoma yielded 24 reported cases in the English-language literature.^1-17 It consists of an admixed population of basaloid matrical and supramatrical cells, ghost cells, and dendritic melanocytes in a well-circumscribed dermal nodule, typically without epidermal or adnexal connection. In comparison to the more commonly described pilomatricoma, which can be uncommonly pigmented, MM typically has only focal areas of ghost cells and lacks cystic architecture.^1,9,10,18 A granulomatous reaction to keratinaceous debris is variably present.^1,9,10 Histologically, the scattered dendritic melanocytes are classically benign, but cases demonstrating melanocyte atypia have been reported.^10,13 Melanocytic matricoma appears most commonly as a black or gray papule on sun-damaged skin in older men and tends not to recur following complete excision; thus, MM is considered to be a clinically benign neoplasm. Given the demographics and distribution of the lesions, exposure to UV radiation is thought to play a contributory role in the pathogenesis.^2,10,19 Melanocytic matricoma is believed to recapitulate the hair follicle in the anagen phase, where there is close interplay between matrical keratinocytes and melanocytes prior to cessation of melanogenesis during the catagen phase.^5,6,8,20,21 Evidence demonstrating highly conserved β-catenin and downstream lymphoid enhancer binding factor 1 (LEF1) expression, as well as pleckstrin homology-like domain, family A, member 1 (PHLDA1) expression (as a marker for follicular stem cells), points to constitutive activity in the Wnt signaling pathway in follicular stem cells of the bulge area as a major agent of tumorigenesis.¹²

Melanocytic matrical carcinoma, also known as malignant MM or matrical carcinoma with melanocytic hyperplasia, may be considered the malignant counterpart to MM.²² A PubMed search of articles indexed for MEDLINE using the terms melanocytic matrical carcinoma, malignant melanocytic matricoma, and matrical carcinoma with melanocytic hyperplasia, with review of references to identify additional citations, yielded 13 reported cases of MMC in the English-language literature (Table).^19,22-30 As with MM, MMC is a biphasic tumor with basaloid matrical and supramatrical cells; focal areas of ghost cells; and admixed, banal-appearing dendritic melanocytes. However, the basaloid component also demonstrates nuclear atypia, mitoses, occasional ulceration, and variably poor circumscription. Clinically these lesions can mimic pigmented BCC, malignant melanoma, or other malignant adnexal tumors.²⁵ Their natural history is unknown due to few reported cases, but they can be correlated with matrical carcinomas, which were first described by Weedon et al³¹ in 1980. A summary of more than 130 cases of matrical carcinomas in the English-language literature found that MMCs have high rates of local recurrence and metastasize in approximately 13% of cases. Wide local excision demonstrated lower rates of recurrence than simple excision (23% vs 83%), but there were insufficient cases to determine the incidence following Mohs micrographic surgery.³² Melanocytic matrical carcinomas also demonstrate mutations in the β-catenin pathway,pointing to a similar pathogenesis as their benign counterparts or perhaps direct malignant transformation.^25,33,34

A subset of MMCs are combined cutaneous tumors (CCTs) consisting of epithelial neoplasms in close association with malignant melanocytes. Two of the more common variants include dermal squamomelanocytic tumors, a term first used by Pool et al,³⁵ and malignant basomelanocytic tumors, as named by Erickson et al,³⁶ but trichoblastomelanomas and other types have been documented.³⁷ Although CCTs typically occur in the same patient populations as MMCs, namely elderly white men with chronically sun-damaged skin,they exhibit several important distinctions.^37-39 By definition, CCTs have a malignant melanocytic component, whereas melanocytes are nonneoplastic in MMCs. The pathogenesis may differ as well. Various mechanisms for the close association of epithelial tumors and melanoma have been proposed, including field cancerization, tumor collision, tumor-tumor metastases, tumor colonization, and others, though CCTs likely arise through combinations of these processes depending upon their subtype.^37-39 Paracrine signaling may play an important role in the pathogenesis of both tumors.^5,6,8,38 As with MMCs, the prognosis of CCTs is limited by relatively few reported cases. Despite advanced Breslow depths in many cases, these tumors display more indolent behavior suggestive of melanoma in situ rather than invasive melanoma, perhaps due to dependence upon epithelial paracrine factors.^37,39-42

Solid-organ transplant recipients have higher rates of more aggressive malignancies, of which skin cancer is the most common.^43-49 Squamous cell carcinoma of the skin accounts for 95% of cutaneous malignancies in this population and occurs at approximately 65 times the rate of the general population.⁵⁰ The risk of other skin cancers also is increased, though less dramatically, including BCC (10-fold increased risk) and melanoma (2- to 8-fold increased risk).^46,50-53 The cause likely is multifactorial, including older age, history of skin cancer pretransplant, more than 5 years posttransplant, male sex, and incrementally as Fitzpatrick skin type decreases from VI to I.^54-56 Immunosuppressive therapy also plays a role in tumorigenesis. Azathioprine metabolites have specifically been implicated in UVA radiation–induced promutagenic oxidative damage to DNA.⁵⁷ Other studies have found no significant differences in the type of immunosuppressant used but instead have correlated rates of skin cancer to overall immunosuppression.^48,55,58 Lung transplant recipients in particular demonstrate high rates of cutaneous malignancy, likely due in part to the necessity of more potent immunosuppressive regimens. Nearly one-third of patients develop a cutaneous malignancy by 5 years and nearly half by 10 years posttransplant.⁵⁵

We report a rare case of MMC in a solid-organ transplant recipient. We hypothesize that the combination of UV radiation exposure–induced photodamage acquired pretransplant in addition to an aggressive immunosuppressive regimen with azathioprine and other agents posttransplant contributed to the development of this patient’s rare malignancy. Although rare, these tumors should remain in the differential diagnosis of clinicians and pathologists caring for this unique patient population.

To the Editor:

A 68-year-old white man presented with a firm, gradually enlarging, mildly tender, grayish black papule with central ulceration on the left dorsal wrist of 4 months’ duration (Figure 1). His relevant medical history included multiple basal cell carcinomas (BCCs) and squamous cell carcinomas, as well as a single-lung transplant 2 years prior, for which he was on chronic immunosuppressive therapy with azathioprine, everolimus, tacrolimus, and prednisone. The clinical differential diagnosis included pigmented BCC, malignant melanoma, and ulcerated squamous cell carcinoma.

Histologic examination of the lesion (Figure 2) demonstrated irregular nodules of basaloid tumor cells with rounded nuclei, visible nucleoli, and scant cytoplasm involving the dermis. The tumor produced abrupt matrical-type keratinization, forming ghost cells. The lesion also contained frequent mitotic figures, apoptotic cells, focal areas of necrosis, and abundant melanin pigment. Admixed throughout the lesion were pigmented and dendritic melanocytic cells. The overlying epidermis was focally ulcerated with an adjacent localized connection between the tumor and the epidermis. Keratinocyte atypia was found in the surrounding epidermis, which contained melanophages, solar elastosis, and scattered chronic inflammatory cells. An immunohistochemical study (Figure 3) for tyrosinase demonstrated abundant admixed melanocytic cells. β-Catenin expression was shown in both nuclear and cytoplasmic distributions, and there was focal labeling on BerEP4 staining. Based on these findings, a diagnosis of melanocytic matrical carcinoma (MMC) was made.

Melanocytic matricoma (MM), a rare adnexal tumor, was first described in 1999 by Carlson et al.¹ A PubMed search of articles indexed for MEDLINE using the terms melanocytic and matricoma yielded 24 reported cases in the English-language literature.^1-17 It consists of an admixed population of basaloid matrical and supramatrical cells, ghost cells, and dendritic melanocytes in a well-circumscribed dermal nodule, typically without epidermal or adnexal connection. In comparison to the more commonly described pilomatricoma, which can be uncommonly pigmented, MM typically has only focal areas of ghost cells and lacks cystic architecture.^1,9,10,18 A granulomatous reaction to keratinaceous debris is variably present.^1,9,10 Histologically, the scattered dendritic melanocytes are classically benign, but cases demonstrating melanocyte atypia have been reported.^10,13 Melanocytic matricoma appears most commonly as a black or gray papule on sun-damaged skin in older men and tends not to recur following complete excision; thus, MM is considered to be a clinically benign neoplasm. Given the demographics and distribution of the lesions, exposure to UV radiation is thought to play a contributory role in the pathogenesis.^2,10,19 Melanocytic matricoma is believed to recapitulate the hair follicle in the anagen phase, where there is close interplay between matrical keratinocytes and melanocytes prior to cessation of melanogenesis during the catagen phase.^5,6,8,20,21 Evidence demonstrating highly conserved β-catenin and downstream lymphoid enhancer binding factor 1 (LEF1) expression, as well as pleckstrin homology-like domain, family A, member 1 (PHLDA1) expression (as a marker for follicular stem cells), points to constitutive activity in the Wnt signaling pathway in follicular stem cells of the bulge area as a major agent of tumorigenesis.¹²

Melanocytic matrical carcinoma, also known as malignant MM or matrical carcinoma with melanocytic hyperplasia, may be considered the malignant counterpart to MM.²² A PubMed search of articles indexed for MEDLINE using the terms melanocytic matrical carcinoma, malignant melanocytic matricoma, and matrical carcinoma with melanocytic hyperplasia, with review of references to identify additional citations, yielded 13 reported cases of MMC in the English-language literature (Table).^19,22-30 As with MM, MMC is a biphasic tumor with basaloid matrical and supramatrical cells; focal areas of ghost cells; and admixed, banal-appearing dendritic melanocytes. However, the basaloid component also demonstrates nuclear atypia, mitoses, occasional ulceration, and variably poor circumscription. Clinically these lesions can mimic pigmented BCC, malignant melanoma, or other malignant adnexal tumors.²⁵ Their natural history is unknown due to few reported cases, but they can be correlated with matrical carcinomas, which were first described by Weedon et al³¹ in 1980. A summary of more than 130 cases of matrical carcinomas in the English-language literature found that MMCs have high rates of local recurrence and metastasize in approximately 13% of cases. Wide local excision demonstrated lower rates of recurrence than simple excision (23% vs 83%), but there were insufficient cases to determine the incidence following Mohs micrographic surgery.³² Melanocytic matrical carcinomas also demonstrate mutations in the β-catenin pathway,pointing to a similar pathogenesis as their benign counterparts or perhaps direct malignant transformation.^25,33,34

A subset of MMCs are combined cutaneous tumors (CCTs) consisting of epithelial neoplasms in close association with malignant melanocytes. Two of the more common variants include dermal squamomelanocytic tumors, a term first used by Pool et al,³⁵ and malignant basomelanocytic tumors, as named by Erickson et al,³⁶ but trichoblastomelanomas and other types have been documented.³⁷ Although CCTs typically occur in the same patient populations as MMCs, namely elderly white men with chronically sun-damaged skin,they exhibit several important distinctions.^37-39 By definition, CCTs have a malignant melanocytic component, whereas melanocytes are nonneoplastic in MMCs. The pathogenesis may differ as well. Various mechanisms for the close association of epithelial tumors and melanoma have been proposed, including field cancerization, tumor collision, tumor-tumor metastases, tumor colonization, and others, though CCTs likely arise through combinations of these processes depending upon their subtype.^37-39 Paracrine signaling may play an important role in the pathogenesis of both tumors.^5,6,8,38 As with MMCs, the prognosis of CCTs is limited by relatively few reported cases. Despite advanced Breslow depths in many cases, these tumors display more indolent behavior suggestive of melanoma in situ rather than invasive melanoma, perhaps due to dependence upon epithelial paracrine factors.^37,39-42

Solid-organ transplant recipients have higher rates of more aggressive malignancies, of which skin cancer is the most common.^43-49 Squamous cell carcinoma of the skin accounts for 95% of cutaneous malignancies in this population and occurs at approximately 65 times the rate of the general population.⁵⁰ The risk of other skin cancers also is increased, though less dramatically, including BCC (10-fold increased risk) and melanoma (2- to 8-fold increased risk).^46,50-53 The cause likely is multifactorial, including older age, history of skin cancer pretransplant, more than 5 years posttransplant, male sex, and incrementally as Fitzpatrick skin type decreases from VI to I.^54-56 Immunosuppressive therapy also plays a role in tumorigenesis. Azathioprine metabolites have specifically been implicated in UVA radiation–induced promutagenic oxidative damage to DNA.⁵⁷ Other studies have found no significant differences in the type of immunosuppressant used but instead have correlated rates of skin cancer to overall immunosuppression.^48,55,58 Lung transplant recipients in particular demonstrate high rates of cutaneous malignancy, likely due in part to the necessity of more potent immunosuppressive regimens. Nearly one-third of patients develop a cutaneous malignancy by 5 years and nearly half by 10 years posttransplant.⁵⁵

We report a rare case of MMC in a solid-organ transplant recipient. We hypothesize that the combination of UV radiation exposure–induced photodamage acquired pretransplant in addition to an aggressive immunosuppressive regimen with azathioprine and other agents posttransplant contributed to the development of this patient’s rare malignancy. Although rare, these tumors should remain in the differential diagnosis of clinicians and pathologists caring for this unique patient population.

To the Editor:

A 68-year-old white man presented with a firm, gradually enlarging, mildly tender, grayish black papule with central ulceration on the left dorsal wrist of 4 months’ duration (Figure 1). His relevant medical history included multiple basal cell carcinomas (BCCs) and squamous cell carcinomas, as well as a single-lung transplant 2 years prior, for which he was on chronic immunosuppressive therapy with azathioprine, everolimus, tacrolimus, and prednisone. The clinical differential diagnosis included pigmented BCC, malignant melanoma, and ulcerated squamous cell carcinoma.

Histologic examination of the lesion (Figure 2) demonstrated irregular nodules of basaloid tumor cells with rounded nuclei, visible nucleoli, and scant cytoplasm involving the dermis. The tumor produced abrupt matrical-type keratinization, forming ghost cells. The lesion also contained frequent mitotic figures, apoptotic cells, focal areas of necrosis, and abundant melanin pigment. Admixed throughout the lesion were pigmented and dendritic melanocytic cells. The overlying epidermis was focally ulcerated with an adjacent localized connection between the tumor and the epidermis. Keratinocyte atypia was found in the surrounding epidermis, which contained melanophages, solar elastosis, and scattered chronic inflammatory cells. An immunohistochemical study (Figure 3) for tyrosinase demonstrated abundant admixed melanocytic cells. β-Catenin expression was shown in both nuclear and cytoplasmic distributions, and there was focal labeling on BerEP4 staining. Based on these findings, a diagnosis of melanocytic matrical carcinoma (MMC) was made.

Melanocytic matricoma (MM), a rare adnexal tumor, was first described in 1999 by Carlson et al.¹ A PubMed search of articles indexed for MEDLINE using the terms melanocytic and matricoma yielded 24 reported cases in the English-language literature.^1-17 It consists of an admixed population of basaloid matrical and supramatrical cells, ghost cells, and dendritic melanocytes in a well-circumscribed dermal nodule, typically without epidermal or adnexal connection. In comparison to the more commonly described pilomatricoma, which can be uncommonly pigmented, MM typically has only focal areas of ghost cells and lacks cystic architecture.^1,9,10,18 A granulomatous reaction to keratinaceous debris is variably present.^1,9,10 Histologically, the scattered dendritic melanocytes are classically benign, but cases demonstrating melanocyte atypia have been reported.^10,13 Melanocytic matricoma appears most commonly as a black or gray papule on sun-damaged skin in older men and tends not to recur following complete excision; thus, MM is considered to be a clinically benign neoplasm. Given the demographics and distribution of the lesions, exposure to UV radiation is thought to play a contributory role in the pathogenesis.^2,10,19 Melanocytic matricoma is believed to recapitulate the hair follicle in the anagen phase, where there is close interplay between matrical keratinocytes and melanocytes prior to cessation of melanogenesis during the catagen phase.^5,6,8,20,21 Evidence demonstrating highly conserved β-catenin and downstream lymphoid enhancer binding factor 1 (LEF1) expression, as well as pleckstrin homology-like domain, family A, member 1 (PHLDA1) expression (as a marker for follicular stem cells), points to constitutive activity in the Wnt signaling pathway in follicular stem cells of the bulge area as a major agent of tumorigenesis.¹²

Melanocytic matrical carcinoma, also known as malignant MM or matrical carcinoma with melanocytic hyperplasia, may be considered the malignant counterpart to MM.²² A PubMed search of articles indexed for MEDLINE using the terms melanocytic matrical carcinoma, malignant melanocytic matricoma, and matrical carcinoma with melanocytic hyperplasia, with review of references to identify additional citations, yielded 13 reported cases of MMC in the English-language literature (Table).^19,22-30 As with MM, MMC is a biphasic tumor with basaloid matrical and supramatrical cells; focal areas of ghost cells; and admixed, banal-appearing dendritic melanocytes. However, the basaloid component also demonstrates nuclear atypia, mitoses, occasional ulceration, and variably poor circumscription. Clinically these lesions can mimic pigmented BCC, malignant melanoma, or other malignant adnexal tumors.²⁵ Their natural history is unknown due to few reported cases, but they can be correlated with matrical carcinomas, which were first described by Weedon et al³¹ in 1980. A summary of more than 130 cases of matrical carcinomas in the English-language literature found that MMCs have high rates of local recurrence and metastasize in approximately 13% of cases. Wide local excision demonstrated lower rates of recurrence than simple excision (23% vs 83%), but there were insufficient cases to determine the incidence following Mohs micrographic surgery.³² Melanocytic matrical carcinomas also demonstrate mutations in the β-catenin pathway,pointing to a similar pathogenesis as their benign counterparts or perhaps direct malignant transformation.^25,33,34

A subset of MMCs are combined cutaneous tumors (CCTs) consisting of epithelial neoplasms in close association with malignant melanocytes. Two of the more common variants include dermal squamomelanocytic tumors, a term first used by Pool et al,³⁵ and malignant basomelanocytic tumors, as named by Erickson et al,³⁶ but trichoblastomelanomas and other types have been documented.³⁷ Although CCTs typically occur in the same patient populations as MMCs, namely elderly white men with chronically sun-damaged skin,they exhibit several important distinctions.^37-39 By definition, CCTs have a malignant melanocytic component, whereas melanocytes are nonneoplastic in MMCs. The pathogenesis may differ as well. Various mechanisms for the close association of epithelial tumors and melanoma have been proposed, including field cancerization, tumor collision, tumor-tumor metastases, tumor colonization, and others, though CCTs likely arise through combinations of these processes depending upon their subtype.^37-39 Paracrine signaling may play an important role in the pathogenesis of both tumors.^5,6,8,38 As with MMCs, the prognosis of CCTs is limited by relatively few reported cases. Despite advanced Breslow depths in many cases, these tumors display more indolent behavior suggestive of melanoma in situ rather than invasive melanoma, perhaps due to dependence upon epithelial paracrine factors.^37,39-42

Solid-organ transplant recipients have higher rates of more aggressive malignancies, of which skin cancer is the most common.^43-49 Squamous cell carcinoma of the skin accounts for 95% of cutaneous malignancies in this population and occurs at approximately 65 times the rate of the general population.⁵⁰ The risk of other skin cancers also is increased, though less dramatically, including BCC (10-fold increased risk) and melanoma (2- to 8-fold increased risk).^46,50-53 The cause likely is multifactorial, including older age, history of skin cancer pretransplant, more than 5 years posttransplant, male sex, and incrementally as Fitzpatrick skin type decreases from VI to I.^54-56 Immunosuppressive therapy also plays a role in tumorigenesis. Azathioprine metabolites have specifically been implicated in UVA radiation–induced promutagenic oxidative damage to DNA.⁵⁷ Other studies have found no significant differences in the type of immunosuppressant used but instead have correlated rates of skin cancer to overall immunosuppression.^48,55,58 Lung transplant recipients in particular demonstrate high rates of cutaneous malignancy, likely due in part to the necessity of more potent immunosuppressive regimens. Nearly one-third of patients develop a cutaneous malignancy by 5 years and nearly half by 10 years posttransplant.⁵⁵

We report a rare case of MMC in a solid-organ transplant recipient. We hypothesize that the combination of UV radiation exposure–induced photodamage acquired pretransplant in addition to an aggressive immunosuppressive regimen with azathioprine and other agents posttransplant contributed to the development of this patient’s rare malignancy. Although rare, these tumors should remain in the differential diagnosis of clinicians and pathologists caring for this unique patient population.

Vandetanib is a once-daily oral multikinase inhibitor that targets the rearranged during transfection (RET) tyrosine kinase, vascular endothelial growth factor receptor, and epidermal growth factor receptor. It has shown efficacy at doses of 300 mg daily in the treatment of progressive medullary thyroid cancer and has shown promise in non–small cell lung cancer and breast cancer. Vandetanib’s toxicity profile includes QT prolongation, diarrhea, and rash.^1-3 Cutaneous involvement has been described in the literature as a photodistributed drug reaction with both erythema multiforme (EM) and Stevens-Johnson syndrome (SJS)–like eruptions, phototoxicity, and photoallergy (Table).^4-12 Photoinduction is the common thread, but various mechanisms have been proposed, including drug deposition within the dermis and direct toxicity to keratinocytes; however, an understanding of the varied presentation is lacking.

We present 3 cases of vandetanib photoinduced cutaneous toxicities and review the literature on this novel kinase inhibitor. This discussion highlights the spectrum of photosensitivity reactions to vandetanib among patients with varying histologic and clinical presentations.

Case Reports

Patient 1A
74-year-old woman with a history of recurrent metastatic squamous cell carcinoma of the cervix and Fitzpatrick skin type III presented with erythematous, well-demarcated, photodistributed, eczematous papules that were coalescing into plaques on the scalp, hands, and face. The rash appeared sharply demarcated at the wrists bilaterally and principally involved the dorsal sun-exposed areas of her hands (Figure 1). The rash also involved the face and the V of the neck with sharp demarcation. Two weeks prior to onset, she initiated a phase 1 trial of oral vandetanib 100 mg twice daily and oral everolimus 5 mg daily. She did not recall practicing sun protection or experiencing increased sun exposure after starting that trial. The patient demonstrated symptom improvement with desonide cream, hydrocortisone cream 2.5%, and over-the-counter analgesic cream while continuing with the study drugs. However, she developed new, warm, painful papules on the hands and face. Phototesting and biopsy were not performed, and the etiology of the photosensitivity was unknown.

The patient was counseled about regular sun protection and was prescribed triamcinolone cream 0.1% for the arms and hydrocortisone cream 2.5% for the affected facial areas. Therapy with vandetanib and everolimus was continued without dose reduction or further cutaneous eruptions.

Patient 2
A 54-year-old man with a history of progressive medullary thyroid carcinoma and Fitzpatrick skin type II presented with erythematous, well-demarcated, photodistributed, edematous plaques and bullae of the head and neck, bilateral dorsal hands, and bilateral palms of 2 weeks’ duration. The rash spared the upper back and chest with a well-demarcated border (Figure 2A). There were ulcerations and erosions at the base of the neck and the dorsal hands (Figure 2B). He also had conjunctivitis but uninvolved oral and genital mucosae.

Two weeks before the rash appeared, oral vandetanib 300 mg daily was initiated. The patient initially noted some dry skin, which progressed to an eruption involving the face and neck and later the hands with palmar blistering and desquamation. Medication cessation for 1 month led to moderate improvement of the rash on the face and neck. He had not been practicing sun protection but did wear a baseball cap when outside. The patient did not recall an incidence of increased sun exposure. He underwent a skin biopsy of the right dorsal hand, which revealed interface dermatitis with dyskeratosis and subepidermal and intraepidermal bullae (Figure 3). The biopsy findings were most consistent with a phototoxic eruption. Phototesting was not performed.

Patient 3
A 73-year-old man with a history of metastatic lung carcinoma and Fitzpatrick skin type II presented with a rash on the scalp, face, and arms of 2.5 weeks’ duration. There was sharp demarcation at the edges of sun-exposed skin, and no bullae were noted (Figure 4). Prior to presentation, the patient started a 4-week phase 1 trial with vandetanib 300 mg daily and everolimus 10 mg daily. He did not recall any episodes of increased sun exposure. A punch biopsy of the arm showed an interface dermatitis suggestive of a phototoxic reaction. Phototesting was not performed to further clarify if there was a diminished minimal erythema dose with UVA or UVB radiation. Both drugs were discontinued, strict photoprotection was practiced, and triamcinolone cream 0.1% was initiated with resolution of rash. Vandetanib and everolimus were resumed at initial doses with strict photoprotection, and the rash has not recurred.

Comment

Adverse Events Associated With Vandetanib
Vandetanib is a novel multikinase inhibitor that targets RET tyrosine kinase, vascular endothelial growth factor receptor, and epidermal growth factor receptor.^1,2 It currently is approved by the US Food and Drug Administration for the treatment of progressive medullary thyroid cancer and is being used in clinical trials for non–small cell lung cancer, glioma, advanced biliary tract cancer, breast cancer, and other advanced solid malignancies. Frequently reported adverse events (AEs) include QT prolongation, diarrhea, and rash.^1-3 In a large phase 3 trial, 45% of patients had a rash; of these, 4% were grade 3 and above.³ The most common reasons for dose decrease or cessation were diarrhea and rash (1% and 1.3%, respectively).¹³ Outside of a trial setting, 75% (45/60) of patients in one French study reported a cutaneous AE, with photosensitivity noted in 22% (13/60). Thus, cutaneous reactions tend to be a common occurrence for patients on this drug, requiring diligent dermatologic examinations.¹⁴ In one meta-analysis comprising 9 studies with a total of 2961 patients, the incidence of all-grade rash was 46.1% (95% CI, 40.6%-51.8%), and it was concluded that vandetanib has the highest association of all-grade rash among the anti–vascular endothelial growth factor tyrosine kinase inhibitors. In this meta-analysis, the specific diagnosis of AEs was not further classified.¹⁵ In another cohort of vandetanib-treated patients, as many as 37% (28/63) of patients had photosensitivity, with no clarification of the etiology.¹⁶

Photoallergic vs Phototoxic Reactions
Photosensitivity reactions are cutaneous reactions that occur from UV light exposure, typically in conjunction with a photosensitizing agent. Photosensitivity reactions can be further classified into phototoxic and photoallergic reactions, which can be distinguished by histopathologic evaluation and history. Although phototoxic reactions will cause keratinocyte necrosis similar to a sunburn, photoallergic reactions will cause epidermal spongiosis similar to allergic contact dermatitis or eczema. Also, phototoxic reactions appear within 1 to 2 days of UV exposure and often are painful, whereas photoallergic reactions can be delayed for 2 to 3 weeks and usually are pruritic. Photosensitivity reactions related to vandetanib have been reported and are summarized in the Table.^4-12

Although reported cutaneous reactions to vandetanib thus far in the literature were reported as photoinduced reactions, there have been isolated case reports of other eruptions including cutaneous pigmentation⁵ and one case of SJS.⁹ According to a PubMed search of articles indexed for MEDLINE using the terms vandetanib and rash, we found that there are a variety of clinical findings, but most of the reported photosensitivity cases were phototoxic. Fava et al⁷ and Goldstein et al¹² both reported 1 photoallergic reaction each, plus patient 1 in our case series was noted to have a photoallergic reaction. Phototoxic reactions were reported in 4 patients (including our patient 2) who had dyskeratotic keratinocytes and vacuolar degeneration of the basal layer on histopathology.^4,8 Fava et al⁷ described a lichenoid infiltrate with spongiosis consistent with a photoallergic reaction, but Chang et al⁴ and Bota et al¹¹ described a lichenoid infiltrate with dyskeratotic cells. Also, Giacchero et al¹⁶ described a photosensitivity reaction in 28 of 63 patients. Although only 6 patients had biopsies performed, the range of photosensitivity reactions was demonstrated with lichenoid, dyskeratotic, and spongiotic reactions. However, the cases were not further defined as photoallergic or phototoxic.¹⁶ Vandetanib also has been associated with cutaneous blue pigmentation after likely phototoxic reactions. Pigment changes occurred after photosensitivity, but the clinical presentation of photosensitivity was not further characterized.^5,16

Classic Drug Eruptions
Two patients were described as having classic drug eruptions—EM¹⁰ and SJS⁹—in photodistributed locations. Histologically, these entities are identical to phototoxic reactions, resulting in epidermal necrosis and an interface dermatitis, but the presence of targetoid lesions on the palms prompted the diagnosis of photodistributed EM and SJS in both cases.^9,10 Unique to the SJS case was oral involvement.⁹

Distinguishing between a phototoxic reaction and photodistributed EM or SJS may be inconsequential if both can be prevented with photoprotection. Rechallenging patients with vandetanib while practicing photoprotection would help to clarify the mechanism, though this course is not always practical.

Mechanism of Action
As seen in our case series, cutaneous reactions occurred only on sun-exposed surfaces, and patients presented with sharp cutoff points that spared non–sun-exposed areas. Although clinically organized as a subtype of photosensitivity, the phototoxicity mechanism of action is considered a direct toxic effect on keratinocytes, which explains the histopathologic finding of dyskeratotic cells and the clinical spectrum of sunburn reaction, phototoxic EM, and SJS. UVA1 induces 2 photoproducts of vandetanib via a UVA1-mediated debromination process,¹⁷ but these photoproducts are not responsible for epidermal dyskeratosis.¹⁸ It was subsequently demonstrated that keratinocyte death was induced by apoptosis through photoinduced DNA cleavage and the formation of an aryl radical, which can induce further DNA damage.¹⁸ Caro-Gutierrez et al¹⁰ demonstrated a lowered minimal erythema dose in their patient with vandetanib-induced phototoxic EM.

Conversely, photoallergic reactions are considered immune-mediated delayed-type hypersensitivity reactions.^4,7,11 Although the mechanism of a photoallergic reaction remains unclear, it is possible that vandetanib or a metabolite (in susceptible patients) induces an immune-mediated delayed-type hypersensitivity reaction with repeated exposure to the compound, which may explain the varied timing of photoallergic onset, including the events featured in the Bota et al¹¹ case that occurred several months after drug initiation.

Conclusion

Considering the high prevalence of cutaneous AEs, especially varied photosensitivity reactions, these cases emphasize the importance of sun protection to help prevent dose reduction or drug cessation among patients taking vandetanib therapy.

Vandetanib is a once-daily oral multikinase inhibitor that targets the rearranged during transfection (RET) tyrosine kinase, vascular endothelial growth factor receptor, and epidermal growth factor receptor. It has shown efficacy at doses of 300 mg daily in the treatment of progressive medullary thyroid cancer and has shown promise in non–small cell lung cancer and breast cancer. Vandetanib’s toxicity profile includes QT prolongation, diarrhea, and rash.^1-3 Cutaneous involvement has been described in the literature as a photodistributed drug reaction with both erythema multiforme (EM) and Stevens-Johnson syndrome (SJS)–like eruptions, phototoxicity, and photoallergy (Table).^4-12 Photoinduction is the common thread, but various mechanisms have been proposed, including drug deposition within the dermis and direct toxicity to keratinocytes; however, an understanding of the varied presentation is lacking.

We present 3 cases of vandetanib photoinduced cutaneous toxicities and review the literature on this novel kinase inhibitor. This discussion highlights the spectrum of photosensitivity reactions to vandetanib among patients with varying histologic and clinical presentations.

Case Reports

Patient 1A
74-year-old woman with a history of recurrent metastatic squamous cell carcinoma of the cervix and Fitzpatrick skin type III presented with erythematous, well-demarcated, photodistributed, eczematous papules that were coalescing into plaques on the scalp, hands, and face. The rash appeared sharply demarcated at the wrists bilaterally and principally involved the dorsal sun-exposed areas of her hands (Figure 1). The rash also involved the face and the V of the neck with sharp demarcation. Two weeks prior to onset, she initiated a phase 1 trial of oral vandetanib 100 mg twice daily and oral everolimus 5 mg daily. She did not recall practicing sun protection or experiencing increased sun exposure after starting that trial. The patient demonstrated symptom improvement with desonide cream, hydrocortisone cream 2.5%, and over-the-counter analgesic cream while continuing with the study drugs. However, she developed new, warm, painful papules on the hands and face. Phototesting and biopsy were not performed, and the etiology of the photosensitivity was unknown.

The patient was counseled about regular sun protection and was prescribed triamcinolone cream 0.1% for the arms and hydrocortisone cream 2.5% for the affected facial areas. Therapy with vandetanib and everolimus was continued without dose reduction or further cutaneous eruptions.

Patient 2
A 54-year-old man with a history of progressive medullary thyroid carcinoma and Fitzpatrick skin type II presented with erythematous, well-demarcated, photodistributed, edematous plaques and bullae of the head and neck, bilateral dorsal hands, and bilateral palms of 2 weeks’ duration. The rash spared the upper back and chest with a well-demarcated border (Figure 2A). There were ulcerations and erosions at the base of the neck and the dorsal hands (Figure 2B). He also had conjunctivitis but uninvolved oral and genital mucosae.

Two weeks before the rash appeared, oral vandetanib 300 mg daily was initiated. The patient initially noted some dry skin, which progressed to an eruption involving the face and neck and later the hands with palmar blistering and desquamation. Medication cessation for 1 month led to moderate improvement of the rash on the face and neck. He had not been practicing sun protection but did wear a baseball cap when outside. The patient did not recall an incidence of increased sun exposure. He underwent a skin biopsy of the right dorsal hand, which revealed interface dermatitis with dyskeratosis and subepidermal and intraepidermal bullae (Figure 3). The biopsy findings were most consistent with a phototoxic eruption. Phototesting was not performed.

Patient 3
A 73-year-old man with a history of metastatic lung carcinoma and Fitzpatrick skin type II presented with a rash on the scalp, face, and arms of 2.5 weeks’ duration. There was sharp demarcation at the edges of sun-exposed skin, and no bullae were noted (Figure 4). Prior to presentation, the patient started a 4-week phase 1 trial with vandetanib 300 mg daily and everolimus 10 mg daily. He did not recall any episodes of increased sun exposure. A punch biopsy of the arm showed an interface dermatitis suggestive of a phototoxic reaction. Phototesting was not performed to further clarify if there was a diminished minimal erythema dose with UVA or UVB radiation. Both drugs were discontinued, strict photoprotection was practiced, and triamcinolone cream 0.1% was initiated with resolution of rash. Vandetanib and everolimus were resumed at initial doses with strict photoprotection, and the rash has not recurred.

Comment

Adverse Events Associated With Vandetanib
Vandetanib is a novel multikinase inhibitor that targets RET tyrosine kinase, vascular endothelial growth factor receptor, and epidermal growth factor receptor.^1,2 It currently is approved by the US Food and Drug Administration for the treatment of progressive medullary thyroid cancer and is being used in clinical trials for non–small cell lung cancer, glioma, advanced biliary tract cancer, breast cancer, and other advanced solid malignancies. Frequently reported adverse events (AEs) include QT prolongation, diarrhea, and rash.^1-3 In a large phase 3 trial, 45% of patients had a rash; of these, 4% were grade 3 and above.³ The most common reasons for dose decrease or cessation were diarrhea and rash (1% and 1.3%, respectively).¹³ Outside of a trial setting, 75% (45/60) of patients in one French study reported a cutaneous AE, with photosensitivity noted in 22% (13/60). Thus, cutaneous reactions tend to be a common occurrence for patients on this drug, requiring diligent dermatologic examinations.¹⁴ In one meta-analysis comprising 9 studies with a total of 2961 patients, the incidence of all-grade rash was 46.1% (95% CI, 40.6%-51.8%), and it was concluded that vandetanib has the highest association of all-grade rash among the anti–vascular endothelial growth factor tyrosine kinase inhibitors. In this meta-analysis, the specific diagnosis of AEs was not further classified.¹⁵ In another cohort of vandetanib-treated patients, as many as 37% (28/63) of patients had photosensitivity, with no clarification of the etiology.¹⁶

Photoallergic vs Phototoxic Reactions
Photosensitivity reactions are cutaneous reactions that occur from UV light exposure, typically in conjunction with a photosensitizing agent. Photosensitivity reactions can be further classified into phototoxic and photoallergic reactions, which can be distinguished by histopathologic evaluation and history. Although phototoxic reactions will cause keratinocyte necrosis similar to a sunburn, photoallergic reactions will cause epidermal spongiosis similar to allergic contact dermatitis or eczema. Also, phototoxic reactions appear within 1 to 2 days of UV exposure and often are painful, whereas photoallergic reactions can be delayed for 2 to 3 weeks and usually are pruritic. Photosensitivity reactions related to vandetanib have been reported and are summarized in the Table.^4-12

Although reported cutaneous reactions to vandetanib thus far in the literature were reported as photoinduced reactions, there have been isolated case reports of other eruptions including cutaneous pigmentation⁵ and one case of SJS.⁹ According to a PubMed search of articles indexed for MEDLINE using the terms vandetanib and rash, we found that there are a variety of clinical findings, but most of the reported photosensitivity cases were phototoxic. Fava et al⁷ and Goldstein et al¹² both reported 1 photoallergic reaction each, plus patient 1 in our case series was noted to have a photoallergic reaction. Phototoxic reactions were reported in 4 patients (including our patient 2) who had dyskeratotic keratinocytes and vacuolar degeneration of the basal layer on histopathology.^4,8 Fava et al⁷ described a lichenoid infiltrate with spongiosis consistent with a photoallergic reaction, but Chang et al⁴ and Bota et al¹¹ described a lichenoid infiltrate with dyskeratotic cells. Also, Giacchero et al¹⁶ described a photosensitivity reaction in 28 of 63 patients. Although only 6 patients had biopsies performed, the range of photosensitivity reactions was demonstrated with lichenoid, dyskeratotic, and spongiotic reactions. However, the cases were not further defined as photoallergic or phototoxic.¹⁶ Vandetanib also has been associated with cutaneous blue pigmentation after likely phototoxic reactions. Pigment changes occurred after photosensitivity, but the clinical presentation of photosensitivity was not further characterized.^5,16

Classic Drug Eruptions
Two patients were described as having classic drug eruptions—EM¹⁰ and SJS⁹—in photodistributed locations. Histologically, these entities are identical to phototoxic reactions, resulting in epidermal necrosis and an interface dermatitis, but the presence of targetoid lesions on the palms prompted the diagnosis of photodistributed EM and SJS in both cases.^9,10 Unique to the SJS case was oral involvement.⁹

Distinguishing between a phototoxic reaction and photodistributed EM or SJS may be inconsequential if both can be prevented with photoprotection. Rechallenging patients with vandetanib while practicing photoprotection would help to clarify the mechanism, though this course is not always practical.

Mechanism of Action
As seen in our case series, cutaneous reactions occurred only on sun-exposed surfaces, and patients presented with sharp cutoff points that spared non–sun-exposed areas. Although clinically organized as a subtype of photosensitivity, the phototoxicity mechanism of action is considered a direct toxic effect on keratinocytes, which explains the histopathologic finding of dyskeratotic cells and the clinical spectrum of sunburn reaction, phototoxic EM, and SJS. UVA1 induces 2 photoproducts of vandetanib via a UVA1-mediated debromination process,¹⁷ but these photoproducts are not responsible for epidermal dyskeratosis.¹⁸ It was subsequently demonstrated that keratinocyte death was induced by apoptosis through photoinduced DNA cleavage and the formation of an aryl radical, which can induce further DNA damage.¹⁸ Caro-Gutierrez et al¹⁰ demonstrated a lowered minimal erythema dose in their patient with vandetanib-induced phototoxic EM.

Conversely, photoallergic reactions are considered immune-mediated delayed-type hypersensitivity reactions.^4,7,11 Although the mechanism of a photoallergic reaction remains unclear, it is possible that vandetanib or a metabolite (in susceptible patients) induces an immune-mediated delayed-type hypersensitivity reaction with repeated exposure to the compound, which may explain the varied timing of photoallergic onset, including the events featured in the Bota et al¹¹ case that occurred several months after drug initiation.

Conclusion

Considering the high prevalence of cutaneous AEs, especially varied photosensitivity reactions, these cases emphasize the importance of sun protection to help prevent dose reduction or drug cessation among patients taking vandetanib therapy.

Vandetanib is a once-daily oral multikinase inhibitor that targets the rearranged during transfection (RET) tyrosine kinase, vascular endothelial growth factor receptor, and epidermal growth factor receptor. It has shown efficacy at doses of 300 mg daily in the treatment of progressive medullary thyroid cancer and has shown promise in non–small cell lung cancer and breast cancer. Vandetanib’s toxicity profile includes QT prolongation, diarrhea, and rash.^1-3 Cutaneous involvement has been described in the literature as a photodistributed drug reaction with both erythema multiforme (EM) and Stevens-Johnson syndrome (SJS)–like eruptions, phototoxicity, and photoallergy (Table).^4-12 Photoinduction is the common thread, but various mechanisms have been proposed, including drug deposition within the dermis and direct toxicity to keratinocytes; however, an understanding of the varied presentation is lacking.

We present 3 cases of vandetanib photoinduced cutaneous toxicities and review the literature on this novel kinase inhibitor. This discussion highlights the spectrum of photosensitivity reactions to vandetanib among patients with varying histologic and clinical presentations.

Case Reports

Patient 1A
74-year-old woman with a history of recurrent metastatic squamous cell carcinoma of the cervix and Fitzpatrick skin type III presented with erythematous, well-demarcated, photodistributed, eczematous papules that were coalescing into plaques on the scalp, hands, and face. The rash appeared sharply demarcated at the wrists bilaterally and principally involved the dorsal sun-exposed areas of her hands (Figure 1). The rash also involved the face and the V of the neck with sharp demarcation. Two weeks prior to onset, she initiated a phase 1 trial of oral vandetanib 100 mg twice daily and oral everolimus 5 mg daily. She did not recall practicing sun protection or experiencing increased sun exposure after starting that trial. The patient demonstrated symptom improvement with desonide cream, hydrocortisone cream 2.5%, and over-the-counter analgesic cream while continuing with the study drugs. However, she developed new, warm, painful papules on the hands and face. Phototesting and biopsy were not performed, and the etiology of the photosensitivity was unknown.

The patient was counseled about regular sun protection and was prescribed triamcinolone cream 0.1% for the arms and hydrocortisone cream 2.5% for the affected facial areas. Therapy with vandetanib and everolimus was continued without dose reduction or further cutaneous eruptions.

Patient 2
A 54-year-old man with a history of progressive medullary thyroid carcinoma and Fitzpatrick skin type II presented with erythematous, well-demarcated, photodistributed, edematous plaques and bullae of the head and neck, bilateral dorsal hands, and bilateral palms of 2 weeks’ duration. The rash spared the upper back and chest with a well-demarcated border (Figure 2A). There were ulcerations and erosions at the base of the neck and the dorsal hands (Figure 2B). He also had conjunctivitis but uninvolved oral and genital mucosae.

Two weeks before the rash appeared, oral vandetanib 300 mg daily was initiated. The patient initially noted some dry skin, which progressed to an eruption involving the face and neck and later the hands with palmar blistering and desquamation. Medication cessation for 1 month led to moderate improvement of the rash on the face and neck. He had not been practicing sun protection but did wear a baseball cap when outside. The patient did not recall an incidence of increased sun exposure. He underwent a skin biopsy of the right dorsal hand, which revealed interface dermatitis with dyskeratosis and subepidermal and intraepidermal bullae (Figure 3). The biopsy findings were most consistent with a phototoxic eruption. Phototesting was not performed.

Patient 3
A 73-year-old man with a history of metastatic lung carcinoma and Fitzpatrick skin type II presented with a rash on the scalp, face, and arms of 2.5 weeks’ duration. There was sharp demarcation at the edges of sun-exposed skin, and no bullae were noted (Figure 4). Prior to presentation, the patient started a 4-week phase 1 trial with vandetanib 300 mg daily and everolimus 10 mg daily. He did not recall any episodes of increased sun exposure. A punch biopsy of the arm showed an interface dermatitis suggestive of a phototoxic reaction. Phototesting was not performed to further clarify if there was a diminished minimal erythema dose with UVA or UVB radiation. Both drugs were discontinued, strict photoprotection was practiced, and triamcinolone cream 0.1% was initiated with resolution of rash. Vandetanib and everolimus were resumed at initial doses with strict photoprotection, and the rash has not recurred.

Comment

Adverse Events Associated With Vandetanib
Vandetanib is a novel multikinase inhibitor that targets RET tyrosine kinase, vascular endothelial growth factor receptor, and epidermal growth factor receptor.^1,2 It currently is approved by the US Food and Drug Administration for the treatment of progressive medullary thyroid cancer and is being used in clinical trials for non–small cell lung cancer, glioma, advanced biliary tract cancer, breast cancer, and other advanced solid malignancies. Frequently reported adverse events (AEs) include QT prolongation, diarrhea, and rash.^1-3 In a large phase 3 trial, 45% of patients had a rash; of these, 4% were grade 3 and above.³ The most common reasons for dose decrease or cessation were diarrhea and rash (1% and 1.3%, respectively).¹³ Outside of a trial setting, 75% (45/60) of patients in one French study reported a cutaneous AE, with photosensitivity noted in 22% (13/60). Thus, cutaneous reactions tend to be a common occurrence for patients on this drug, requiring diligent dermatologic examinations.¹⁴ In one meta-analysis comprising 9 studies with a total of 2961 patients, the incidence of all-grade rash was 46.1% (95% CI, 40.6%-51.8%), and it was concluded that vandetanib has the highest association of all-grade rash among the anti–vascular endothelial growth factor tyrosine kinase inhibitors. In this meta-analysis, the specific diagnosis of AEs was not further classified.¹⁵ In another cohort of vandetanib-treated patients, as many as 37% (28/63) of patients had photosensitivity, with no clarification of the etiology.¹⁶

Photoallergic vs Phototoxic Reactions
Photosensitivity reactions are cutaneous reactions that occur from UV light exposure, typically in conjunction with a photosensitizing agent. Photosensitivity reactions can be further classified into phototoxic and photoallergic reactions, which can be distinguished by histopathologic evaluation and history. Although phototoxic reactions will cause keratinocyte necrosis similar to a sunburn, photoallergic reactions will cause epidermal spongiosis similar to allergic contact dermatitis or eczema. Also, phototoxic reactions appear within 1 to 2 days of UV exposure and often are painful, whereas photoallergic reactions can be delayed for 2 to 3 weeks and usually are pruritic. Photosensitivity reactions related to vandetanib have been reported and are summarized in the Table.^4-12

Although reported cutaneous reactions to vandetanib thus far in the literature were reported as photoinduced reactions, there have been isolated case reports of other eruptions including cutaneous pigmentation⁵ and one case of SJS.⁹ According to a PubMed search of articles indexed for MEDLINE using the terms vandetanib and rash, we found that there are a variety of clinical findings, but most of the reported photosensitivity cases were phototoxic. Fava et al⁷ and Goldstein et al¹² both reported 1 photoallergic reaction each, plus patient 1 in our case series was noted to have a photoallergic reaction. Phototoxic reactions were reported in 4 patients (including our patient 2) who had dyskeratotic keratinocytes and vacuolar degeneration of the basal layer on histopathology.^4,8 Fava et al⁷ described a lichenoid infiltrate with spongiosis consistent with a photoallergic reaction, but Chang et al⁴ and Bota et al¹¹ described a lichenoid infiltrate with dyskeratotic cells. Also, Giacchero et al¹⁶ described a photosensitivity reaction in 28 of 63 patients. Although only 6 patients had biopsies performed, the range of photosensitivity reactions was demonstrated with lichenoid, dyskeratotic, and spongiotic reactions. However, the cases were not further defined as photoallergic or phototoxic.¹⁶ Vandetanib also has been associated with cutaneous blue pigmentation after likely phototoxic reactions. Pigment changes occurred after photosensitivity, but the clinical presentation of photosensitivity was not further characterized.^5,16

Classic Drug Eruptions
Two patients were described as having classic drug eruptions—EM¹⁰ and SJS⁹—in photodistributed locations. Histologically, these entities are identical to phototoxic reactions, resulting in epidermal necrosis and an interface dermatitis, but the presence of targetoid lesions on the palms prompted the diagnosis of photodistributed EM and SJS in both cases.^9,10 Unique to the SJS case was oral involvement.⁹

Distinguishing between a phototoxic reaction and photodistributed EM or SJS may be inconsequential if both can be prevented with photoprotection. Rechallenging patients with vandetanib while practicing photoprotection would help to clarify the mechanism, though this course is not always practical.

Mechanism of Action
As seen in our case series, cutaneous reactions occurred only on sun-exposed surfaces, and patients presented with sharp cutoff points that spared non–sun-exposed areas. Although clinically organized as a subtype of photosensitivity, the phototoxicity mechanism of action is considered a direct toxic effect on keratinocytes, which explains the histopathologic finding of dyskeratotic cells and the clinical spectrum of sunburn reaction, phototoxic EM, and SJS. UVA1 induces 2 photoproducts of vandetanib via a UVA1-mediated debromination process,¹⁷ but these photoproducts are not responsible for epidermal dyskeratosis.¹⁸ It was subsequently demonstrated that keratinocyte death was induced by apoptosis through photoinduced DNA cleavage and the formation of an aryl radical, which can induce further DNA damage.¹⁸ Caro-Gutierrez et al¹⁰ demonstrated a lowered minimal erythema dose in their patient with vandetanib-induced phototoxic EM.

Conversely, photoallergic reactions are considered immune-mediated delayed-type hypersensitivity reactions.^4,7,11 Although the mechanism of a photoallergic reaction remains unclear, it is possible that vandetanib or a metabolite (in susceptible patients) induces an immune-mediated delayed-type hypersensitivity reaction with repeated exposure to the compound, which may explain the varied timing of photoallergic onset, including the events featured in the Bota et al¹¹ case that occurred several months after drug initiation.

Conclusion

Considering the high prevalence of cutaneous AEs, especially varied photosensitivity reactions, these cases emphasize the importance of sun protection to help prevent dose reduction or drug cessation among patients taking vandetanib therapy.

The Diagnosis: Erosive Adenomatosis of the Nipple 

Biopsy of the lesion revealed proliferative sections of glandular epithelium demonstrating apocrine differentiation, connecting to the epidermis and traversing throughout the entire dermis of the specimen (Figure). There were papillary projections of dilated ducts with a retained layer of myoepithelial cells surrounding the epithelial layers. Cytologic atypia was not appreciated. The patient was diagnosed with erosive adenomatosis of the nipple (EAN), also known as nipple adenoma. The lesion subsequently was treated and cleared with Mohs micrographic surgery (MMS). At 8-month follow-up there was no clinical recurrence of the lesion, and the patient was satisfied with the overall cosmetic appearance and conservation of the areola. The patient was followed clinically with annual breast examinations and mammography to monitor future recurrence. 

Erosive adenomatosis of the nipple is an uncommon benign proliferative process of the lactiferous ducts of the nipple. Recognizing EAN is important because it resembles malignant breast diseases such as Paget disease of the nipple and invasive breast carcinoma. Due to these similarities, early cases of EAN have resulted in unnecessary mastectomies before the benignity of the condition was established.¹ Accurate diagnosis is important to both the patient and the clinician for treatment planning as well as psychosocial consequences associated with the potential removal of this anatomically and cosmetically sensitive area. 

Reviewing the literature on EAN is complicated by the variety of terms used to describe this condition, including but not limited to nipple adenoma, nipple duct adenoma, papillary adenoma of the nipple, and florid papillomatosis of the nipple. In 1955, Jones² described EAN using the term florid papillomatosis of the nipple ducts. In 1962, Handley and Thackray¹ argued that adenoma of the nipple was a more descriptive term because it more closely described the appearance of a sweat gland adenoma. They reasoned that adenoma of the nipple is a separate process from ductal papilloma due to the adenomatous proliferation into the nipple stroma rather than the lumen of the nipple ducts.¹ The term adenoma of the nipple was further supported in 1965 by Taylor and Robertson.³ In 1959, Le Gal et al⁴ used the term erosive adenomatosis of the nipple to describe the erosive nature of nipple adenoma. The term nipple adenoma was published in the 2012 WHO Classification of Tumors of the Breast with 4 common histologic subtypes.^5,6  

Erosive adenomatosis of the nipple is clinically indistinguishable from Paget disease of the nipple, thus biopsy is essential for accurate diagnosis. In contrast to Paget disease, EAN tends to present in younger patients and progresses more slowly, and symptoms may be exacerbated around menstruation.¹ Case reports demonstrate that patients may wait years before seeking medical attention for EAN.^1,3,7,8 Presenting symptoms may include inflammation, crusting, nipple skin erosion, itching, and pain. Serous or sanguineous discharge from the lesions also is commonly reported. Palpation may reveal a small, hard, or elastic nodule within or underlying the nipple. In addition to Paget disease, EAN may resemble squamous cell carcinoma of the nipple, eczema, psoriasis, or a skin infection.⁶ Axillary lymphadenopathy is not present in the absence of a concomitant breast malignancy.⁸ On biopsy, nipple adenoma represents ductal proliferation of glandular structures within the stroma of the nipple that is well circumscribed but without borders. The erosive appearance of the lesion is produced by extensions of the glandular epithelium on the surface of the nipple.^1,6 Specific to EAN is the presence of 2 cell types: an inner columnar epithelium and an outer cuboidal myoepithelium. These 2 cell types are present in normal lactiferous ducts; however, normal ducts are highly organized compared to EAN.⁹  

After confirmation of EAN by nipple biopsy, complete surgical excision has been the gold standard for treatment, followed by reconstructive surgery.⁶ Handley and Thackray¹ advocated for total excision of the nipple and areola with an underlying wedge of breast tissue to facilitate wound closure. More recently, successful alternative forms of treatment have been utilized to minimize disfiguring surgery. Alternative treatments include MMS,⁸ cryotherapy,¹⁰ and nipple splitting enucleation.⁶ Treatment with MMS has resulted in nipple sparing with the least amount of surface area sacrificed (1.1 cm2).⁹ Our case and prior case reports demonstrate that the tissue sparing potential of MMS is appropriate for the treatment of EAN, though traditionally it has been reserved for more malignant tumors. Preserving this sensitive area is both cosmetically and psychologically advantageous for the patient and thus should be considered when reviewing treatment options for EAN. 

The Diagnosis: Erosive Adenomatosis of the Nipple 

Biopsy of the lesion revealed proliferative sections of glandular epithelium demonstrating apocrine differentiation, connecting to the epidermis and traversing throughout the entire dermis of the specimen (Figure). There were papillary projections of dilated ducts with a retained layer of myoepithelial cells surrounding the epithelial layers. Cytologic atypia was not appreciated. The patient was diagnosed with erosive adenomatosis of the nipple (EAN), also known as nipple adenoma. The lesion subsequently was treated and cleared with Mohs micrographic surgery (MMS). At 8-month follow-up there was no clinical recurrence of the lesion, and the patient was satisfied with the overall cosmetic appearance and conservation of the areola. The patient was followed clinically with annual breast examinations and mammography to monitor future recurrence. 

Erosive adenomatosis of the nipple is an uncommon benign proliferative process of the lactiferous ducts of the nipple. Recognizing EAN is important because it resembles malignant breast diseases such as Paget disease of the nipple and invasive breast carcinoma. Due to these similarities, early cases of EAN have resulted in unnecessary mastectomies before the benignity of the condition was established.¹ Accurate diagnosis is important to both the patient and the clinician for treatment planning as well as psychosocial consequences associated with the potential removal of this anatomically and cosmetically sensitive area. 

Reviewing the literature on EAN is complicated by the variety of terms used to describe this condition, including but not limited to nipple adenoma, nipple duct adenoma, papillary adenoma of the nipple, and florid papillomatosis of the nipple. In 1955, Jones² described EAN using the term florid papillomatosis of the nipple ducts. In 1962, Handley and Thackray¹ argued that adenoma of the nipple was a more descriptive term because it more closely described the appearance of a sweat gland adenoma. They reasoned that adenoma of the nipple is a separate process from ductal papilloma due to the adenomatous proliferation into the nipple stroma rather than the lumen of the nipple ducts.¹ The term adenoma of the nipple was further supported in 1965 by Taylor and Robertson.³ In 1959, Le Gal et al⁴ used the term erosive adenomatosis of the nipple to describe the erosive nature of nipple adenoma. The term nipple adenoma was published in the 2012 WHO Classification of Tumors of the Breast with 4 common histologic subtypes.^5,6  

Erosive adenomatosis of the nipple is clinically indistinguishable from Paget disease of the nipple, thus biopsy is essential for accurate diagnosis. In contrast to Paget disease, EAN tends to present in younger patients and progresses more slowly, and symptoms may be exacerbated around menstruation.¹ Case reports demonstrate that patients may wait years before seeking medical attention for EAN.^1,3,7,8 Presenting symptoms may include inflammation, crusting, nipple skin erosion, itching, and pain. Serous or sanguineous discharge from the lesions also is commonly reported. Palpation may reveal a small, hard, or elastic nodule within or underlying the nipple. In addition to Paget disease, EAN may resemble squamous cell carcinoma of the nipple, eczema, psoriasis, or a skin infection.⁶ Axillary lymphadenopathy is not present in the absence of a concomitant breast malignancy.⁸ On biopsy, nipple adenoma represents ductal proliferation of glandular structures within the stroma of the nipple that is well circumscribed but without borders. The erosive appearance of the lesion is produced by extensions of the glandular epithelium on the surface of the nipple.^1,6 Specific to EAN is the presence of 2 cell types: an inner columnar epithelium and an outer cuboidal myoepithelium. These 2 cell types are present in normal lactiferous ducts; however, normal ducts are highly organized compared to EAN.⁹  

After confirmation of EAN by nipple biopsy, complete surgical excision has been the gold standard for treatment, followed by reconstructive surgery.⁶ Handley and Thackray¹ advocated for total excision of the nipple and areola with an underlying wedge of breast tissue to facilitate wound closure. More recently, successful alternative forms of treatment have been utilized to minimize disfiguring surgery. Alternative treatments include MMS,⁸ cryotherapy,¹⁰ and nipple splitting enucleation.⁶ Treatment with MMS has resulted in nipple sparing with the least amount of surface area sacrificed (1.1 cm2).⁹ Our case and prior case reports demonstrate that the tissue sparing potential of MMS is appropriate for the treatment of EAN, though traditionally it has been reserved for more malignant tumors. Preserving this sensitive area is both cosmetically and psychologically advantageous for the patient and thus should be considered when reviewing treatment options for EAN. 

The Diagnosis: Erosive Adenomatosis of the Nipple 

Biopsy of the lesion revealed proliferative sections of glandular epithelium demonstrating apocrine differentiation, connecting to the epidermis and traversing throughout the entire dermis of the specimen (Figure). There were papillary projections of dilated ducts with a retained layer of myoepithelial cells surrounding the epithelial layers. Cytologic atypia was not appreciated. The patient was diagnosed with erosive adenomatosis of the nipple (EAN), also known as nipple adenoma. The lesion subsequently was treated and cleared with Mohs micrographic surgery (MMS). At 8-month follow-up there was no clinical recurrence of the lesion, and the patient was satisfied with the overall cosmetic appearance and conservation of the areola. The patient was followed clinically with annual breast examinations and mammography to monitor future recurrence. 

Erosive adenomatosis of the nipple is an uncommon benign proliferative process of the lactiferous ducts of the nipple. Recognizing EAN is important because it resembles malignant breast diseases such as Paget disease of the nipple and invasive breast carcinoma. Due to these similarities, early cases of EAN have resulted in unnecessary mastectomies before the benignity of the condition was established.¹ Accurate diagnosis is important to both the patient and the clinician for treatment planning as well as psychosocial consequences associated with the potential removal of this anatomically and cosmetically sensitive area. 

Reviewing the literature on EAN is complicated by the variety of terms used to describe this condition, including but not limited to nipple adenoma, nipple duct adenoma, papillary adenoma of the nipple, and florid papillomatosis of the nipple. In 1955, Jones² described EAN using the term florid papillomatosis of the nipple ducts. In 1962, Handley and Thackray¹ argued that adenoma of the nipple was a more descriptive term because it more closely described the appearance of a sweat gland adenoma. They reasoned that adenoma of the nipple is a separate process from ductal papilloma due to the adenomatous proliferation into the nipple stroma rather than the lumen of the nipple ducts.¹ The term adenoma of the nipple was further supported in 1965 by Taylor and Robertson.³ In 1959, Le Gal et al⁴ used the term erosive adenomatosis of the nipple to describe the erosive nature of nipple adenoma. The term nipple adenoma was published in the 2012 WHO Classification of Tumors of the Breast with 4 common histologic subtypes.^5,6  

Erosive adenomatosis of the nipple is clinically indistinguishable from Paget disease of the nipple, thus biopsy is essential for accurate diagnosis. In contrast to Paget disease, EAN tends to present in younger patients and progresses more slowly, and symptoms may be exacerbated around menstruation.¹ Case reports demonstrate that patients may wait years before seeking medical attention for EAN.^1,3,7,8 Presenting symptoms may include inflammation, crusting, nipple skin erosion, itching, and pain. Serous or sanguineous discharge from the lesions also is commonly reported. Palpation may reveal a small, hard, or elastic nodule within or underlying the nipple. In addition to Paget disease, EAN may resemble squamous cell carcinoma of the nipple, eczema, psoriasis, or a skin infection.⁶ Axillary lymphadenopathy is not present in the absence of a concomitant breast malignancy.⁸ On biopsy, nipple adenoma represents ductal proliferation of glandular structures within the stroma of the nipple that is well circumscribed but without borders. The erosive appearance of the lesion is produced by extensions of the glandular epithelium on the surface of the nipple.^1,6 Specific to EAN is the presence of 2 cell types: an inner columnar epithelium and an outer cuboidal myoepithelium. These 2 cell types are present in normal lactiferous ducts; however, normal ducts are highly organized compared to EAN.⁹  

After confirmation of EAN by nipple biopsy, complete surgical excision has been the gold standard for treatment, followed by reconstructive surgery.⁶ Handley and Thackray¹ advocated for total excision of the nipple and areola with an underlying wedge of breast tissue to facilitate wound closure. More recently, successful alternative forms of treatment have been utilized to minimize disfiguring surgery. Alternative treatments include MMS,⁸ cryotherapy,¹⁰ and nipple splitting enucleation.⁶ Treatment with MMS has resulted in nipple sparing with the least amount of surface area sacrificed (1.1 cm2).⁹ Our case and prior case reports demonstrate that the tissue sparing potential of MMS is appropriate for the treatment of EAN, though traditionally it has been reserved for more malignant tumors. Preserving this sensitive area is both cosmetically and psychologically advantageous for the patient and thus should be considered when reviewing treatment options for EAN. 

Merkel cell carcinoma (MCC) is an aggressive neuroendocrine malignancy of the skin that is thought to arise from neural crest cells. It has an estimated annual incidence of 0.6 per 100,000 individuals, typically occurs in the elderly population, and is most common in white males.¹ The tumor presents as a rapidly growing, violaceous nodule in sun-exposed areas of the skin; early in the course, it can be mistaken for a benign entity such as an epidermal cyst.² Merkel cell carcinoma has a propensity to spread to regional lymph nodes, and in some cases, it occurs in the absence of skin findings.³ Histologically, MCC is nearly indistinguishable from small cell lung carcinoma (SCLC).⁴ The overall prognosis for patients with MCC is poor and largely dependent on the stage at diagnosis. Patients with regional and distant metastases have a 5-year survival rate of 26% to 42% and 18%, respectively.³

Lambert-Eaton myasthenic syndrome (LEMS) is a paraneoplastic or autoimmune disorder of the neuromuscular junction that is found in 3% of cases of SCLC.⁴ Reported cases of LEMS in patients with MCC are exceedingly rare.^5-8 We provide a full report and longitudinal clinical follow-up of a case that was briefly discussed by Simmons et al,⁸ and we review the literature regarding paraneoplastic syndromes associated with MCC and other extrapulmonary small cell carcinomas (EPSCCs).

Case Report

A 63-year-old man was evaluated in the neurology clinic due to difficulty walking, climbing stairs, and performing push-ups over the last month. Prior to the onset of symptoms, he was otherwise healthy, walking 3 miles daily; however, at presentation he required use of a cane. Leg weakness worsened as the day progressed. In addition, he reported constipation, urinary urgency, dry mouth, mild dysphagia, reduced sensation below the knees, and a nasal quality in his speech. He had no ptosis, diplopia, dysarthria, muscle cramps, myalgia, or facial weakness. He denied fevers, chills, and night sweats but did admit to an unintentional 10- to 15-lb weight loss over the preceding few months.

The neurologic examination revealed mild proximal upper extremity weakness in the bilateral shoulder abductors, infraspinatus, hip extensors, and hip flexors (Medical Research Council muscle scale grade 4). All deep tendon reflexes, except the Achilles reflex, were present. Despite subjective sensory concerns, objective examination of all sensory modalities was normal. Cranial nerve examination was normal, except for a slight nasal quality to his voice.

A qualitative assay was positive for the presence of P/Q-type voltage-gated calcium channel (VGCC) antibodies. Other laboratory studies were within reference range, including acetylcholine-receptor antibodies (blocking, binding, and modulating) and muscle-specific kinase antibodies.

Lumbar and cervical spine magnetic resonance imaging revealed multilevel neuroforaminal stenosis without spinal canal stenosis or myelopathy. Computed tomography (CT) of the chest was notable for 2 pathologically enlarged lymph nodes in the left axilla and no evidence of primary pulmonary malignancy. Nerve-conduction studies (NCSs) in conjunction with other clinical findings were consistent with the diagnosis of LEMS.

Ultrasound-guided biopsy of the enlarged axillary lymph nodes demonstrated sheets and nests of small round blue tumor cells with minimal cytoplasm, high mitotic rate, and foci of necrosis (Figure 1). The tumor cells were positive for pancytokeratin (Lu-5) and cytokeratin (CK) 20 in a perinuclear dotlike pattern (Figure 2), as well as for the neuroendocrine markers synaptophysin (Figure 3), chromogranin A, and CD56. The tumor cells showed no immunoreactivity for CK7, thyroid transcription factor 1, CD3, CD5, or CD20. Flow cytometry demonstrated low cellularity, low specimen viability, and no evidence of an abnormal B-cell population. These findings were consistent with the diagnosis of MCC.

The patient underwent surgical excision of the involved lymph nodes. Four weeks after surgery, he reported dramatic improvement in strength, with complete resolution of the nasal speech, dysphagia, dry mouth, urinary retention, and constipation. Two months after surgery, his strength had normalized, except for slight persistent weakness in the bilateral shoulder abductors, trace weakness in the hip flexors, and a slight Trendelenburg gait. He was able to rise from a chair without using his arms and no longer required a cane for ambulation.

The patient underwent adjuvant radiation therapy after 2-month surgical follow-up with 5000-cGy radiation treatment to the left axillary region. Six months following primary definitive surgery and 4 months following adjuvant radiation therapy, he reported a 95% subjective return of physical strength. The patient was able to return to near-baseline physical activity. He continued to deny symptoms of dry mouth, incontinence, or constipation. Objectively, he had no focal neurologic deficits or weakness; no evidence of new skin lesions or lymphadenopathy was noted.

Comment

MCC vs SCLC
Merkel cell carcinoma is classified as a type of EPSCC. The histologic appearance of MCC is indistinguishable from SCLC. Both tumors are composed of uniform sheets of small round cells with a high nucleus to cytoplasm ratio, and both can express neuroendocrine markers, such as neuron-specific enolase, chromogranin A, and synaptophysin.⁹ Immunohistochemical positivity for CK20 and neurofilaments in combination with negative staining for thyroid transcription factor 1 and CK7 effectively differentiate MCC from SCLC.⁹ In addition, MCC often displays CK20 positivity in a perinuclear dotlike or punctate pattern, which is characteristic of this tumor.^3,9,10 Negative immunohistochemical markers for B cells (CD20) and T cells (CD3) are important in excluding lymphoma.

LEMS Diagnosis
Lambert-Eaton myasthenic syndrome is a paraneoplastic or autoimmune disorder involving the neuromuscular junction. Autoantibodies to VGCC impair calcium influx into the presynaptic terminal, resulting in marked reduction of acetylcholine release into the synaptic cleft. The reduction in acetylcholine activity impairs production of muscle fiber action potentials, resulting in clinical weakness. The diagnosis of LEMS rests on clinical presentation, positive serology, and confirmatory neurophysiologic testing by NCS. Clinically, patients present with proximal weakness, hyporeflexia or areflexia, and autonomic dysfunction. Antibodies to P/Q-type VGCCs are found in 85% to 90% of cases of LEMS and are thought to play a direct causative role in the development of weakness.¹¹ The finding of postexercise facilitation on motor NCS is the neurophysiologic hallmark and is highly specific for the diagnosis.

Approximately 50% to 60% of patients who present with LEMS have an underlying tumor, the vast majority of which are SCLC.¹¹ There are a few reports of LEMS associated with other malignancies, including lymphoma; thymoma; neuroblastoma; and carcinoma of the breast, stomach, prostate, bladder, kidney, and gallbladder.¹² Patients with nontumor or autoimmune LEMS tend to be younger, and there is no male predominance, as there is in paraneoplastic LEMS.¹³ Given the risk of underlying malignancy in LEMS, Titulaer et al¹⁴ proposed a screening protocol for patients presenting with LEMS, recommending initial primary screening using CT of the chest. If the CT scan is negative, total-body fludeoxyglucose positron emission tomography should be performed to assess for fludeoxyglucose avid lesions. If both initial studies are negative, routine follow-up with CT of the chest at 6-month intervals for a minimum of 2 to 4 years after the initial diagnosis of LEMS was recommended. An exception to this protocol was suggested to allow consideration to stop screening after the first 6-month follow-up chest CT for patients younger than 45 years who have never smoked and who have an HLA 8.1 haplotype for which nontumor LEMS would be a more probable diagnosis.¹⁴

In addition to a screening protocol, a validated prediction tool, the Dutch-English LEMS Tumor Association prediction score, was developed. It uses common signs and symptoms of LEMS and risk factors for SCLC to help guide the need for further screening.¹⁵

Paraneoplastic Syndromes Associated With MCC
Other paraneoplastic syndromes have been reported in association with MCC. A patient with brainstem encephalitis associated with MCC was reported in a trial of a novel immunotherapy for paraneoplastic neurologic syndromes.^16,17 A syndrome of inappropriate antidiuretic hormone (SIADH) secretion was reported in a patient with N-type calcium channel antibodies.¹⁸ Two cases of paraneoplastic cerebellar degeneration have been reported; the first was associated with a novel 70-kD antibody,¹⁹ and the second was associated with the P/Q-type VGCC antibody.²⁰ Anti-Hu antibodies have been found in a handful of reports of neurologic deterioration in patients with MCC. Hocar et al²¹ reported a severe necrotizing myopathy; Greenlee et al²² described a syndrome of progressive sensorimotor and autonomic neuropathy with encephalopathy; and Lopez et al²³ described a constellation of vision changes, gait imbalance, and proximal weakness. Support for a pathophysiologic connection among these 3 cases is suggested by the finding of Hu antigen expression by MCC in 2 studies.^24,25 Because MCC can present with occult lymph node involvement in the absence of primary cutaneous findings,³ there are more cases of paraneoplastic neurologic syndromes that were not recognized.

Extrapulmonary small cell carcinomas such as MCC are morphologically indistinguishable from their pulmonary counterparts and have been reported in most anatomic regions of the body, including gynecologic organs (eg, ovaries, cervix), genitourinary organs (eg, bladder, prostate), the gastrointestinal tract (eg, esophagus), skin (eg, MCC), and the head and neck region. Extrapulmonary small cell carcinoma is a rare entity, with the most common form found in the gynecologic tract, representing only 2% of gynecologic malignancies.²⁶

Paraneoplastic syndromes of EPSCC are rare given the paucity of the malignancy. Several case reports discuss findings of SIADH in EPSCC of the cervix, as well as hypercalcemia, polyneuropathy, Cushing syndrome, limbic encephalitis, and peripheral neuropathy in EPSCC of the prostate.^27,28 In contrast, SCLC has long been associated with paraneoplastic syndromes. Numerous case reports have been published describing SCLC-associated paraneoplastic syndromes to include hypercalcemia, Cushing syndrome, SIADH, vasoactive peptide production, cerebellar degeneration, limbic encephalitis, visceral plexopathy, autonomic dysfunction, and LEMS.²⁹ As more cases of EPSCC with paraneoplastic syndromes are identified and reported, we might gain a better understanding of this interesting phenomenon.

Conclusion

Merkel cell carcinoma is an aggressive neuroendocrine malignancy associated with paraneoplastic neurologic syndromes, including LEMS. A thorough search for an underlying malignancy is highly recommended in patients with diagnosed LEMS without clear cause. Early identification and treatment of the primary tumor can lead to improvement of neurologic symptoms.

We present a case of LEMS with no clearly identifiable cause on presentation with later diagnosis of metastatic MCC of unknown primary origin. After surgical excision of affected lymph nodes and adjuvant radiation therapy, the patient had near-complete resolution of LEMS symptoms at 6-month follow-up, without additional findings of lymphadenopathy or skin lesions. Although this patient is not undergoing routine surveillance imaging to monitor for recurrence of MCC, a chest CT or positron emission tomography–CT for secondary screening would be considered if the patient experienced clinical symptoms consistent with LEMS.

In cases of LEMS without pulmonary malignancy, we recommend considering MCC in the differential diagnosis during the workup of an underlying malignancy

Merkel cell carcinoma (MCC) is an aggressive neuroendocrine malignancy of the skin that is thought to arise from neural crest cells. It has an estimated annual incidence of 0.6 per 100,000 individuals, typically occurs in the elderly population, and is most common in white males.¹ The tumor presents as a rapidly growing, violaceous nodule in sun-exposed areas of the skin; early in the course, it can be mistaken for a benign entity such as an epidermal cyst.² Merkel cell carcinoma has a propensity to spread to regional lymph nodes, and in some cases, it occurs in the absence of skin findings.³ Histologically, MCC is nearly indistinguishable from small cell lung carcinoma (SCLC).⁴ The overall prognosis for patients with MCC is poor and largely dependent on the stage at diagnosis. Patients with regional and distant metastases have a 5-year survival rate of 26% to 42% and 18%, respectively.³

Lambert-Eaton myasthenic syndrome (LEMS) is a paraneoplastic or autoimmune disorder of the neuromuscular junction that is found in 3% of cases of SCLC.⁴ Reported cases of LEMS in patients with MCC are exceedingly rare.^5-8 We provide a full report and longitudinal clinical follow-up of a case that was briefly discussed by Simmons et al,⁸ and we review the literature regarding paraneoplastic syndromes associated with MCC and other extrapulmonary small cell carcinomas (EPSCCs).

Case Report

A 63-year-old man was evaluated in the neurology clinic due to difficulty walking, climbing stairs, and performing push-ups over the last month. Prior to the onset of symptoms, he was otherwise healthy, walking 3 miles daily; however, at presentation he required use of a cane. Leg weakness worsened as the day progressed. In addition, he reported constipation, urinary urgency, dry mouth, mild dysphagia, reduced sensation below the knees, and a nasal quality in his speech. He had no ptosis, diplopia, dysarthria, muscle cramps, myalgia, or facial weakness. He denied fevers, chills, and night sweats but did admit to an unintentional 10- to 15-lb weight loss over the preceding few months.

The neurologic examination revealed mild proximal upper extremity weakness in the bilateral shoulder abductors, infraspinatus, hip extensors, and hip flexors (Medical Research Council muscle scale grade 4). All deep tendon reflexes, except the Achilles reflex, were present. Despite subjective sensory concerns, objective examination of all sensory modalities was normal. Cranial nerve examination was normal, except for a slight nasal quality to his voice.

A qualitative assay was positive for the presence of P/Q-type voltage-gated calcium channel (VGCC) antibodies. Other laboratory studies were within reference range, including acetylcholine-receptor antibodies (blocking, binding, and modulating) and muscle-specific kinase antibodies.

Lumbar and cervical spine magnetic resonance imaging revealed multilevel neuroforaminal stenosis without spinal canal stenosis or myelopathy. Computed tomography (CT) of the chest was notable for 2 pathologically enlarged lymph nodes in the left axilla and no evidence of primary pulmonary malignancy. Nerve-conduction studies (NCSs) in conjunction with other clinical findings were consistent with the diagnosis of LEMS.

Ultrasound-guided biopsy of the enlarged axillary lymph nodes demonstrated sheets and nests of small round blue tumor cells with minimal cytoplasm, high mitotic rate, and foci of necrosis (Figure 1). The tumor cells were positive for pancytokeratin (Lu-5) and cytokeratin (CK) 20 in a perinuclear dotlike pattern (Figure 2), as well as for the neuroendocrine markers synaptophysin (Figure 3), chromogranin A, and CD56. The tumor cells showed no immunoreactivity for CK7, thyroid transcription factor 1, CD3, CD5, or CD20. Flow cytometry demonstrated low cellularity, low specimen viability, and no evidence of an abnormal B-cell population. These findings were consistent with the diagnosis of MCC.

The patient underwent surgical excision of the involved lymph nodes. Four weeks after surgery, he reported dramatic improvement in strength, with complete resolution of the nasal speech, dysphagia, dry mouth, urinary retention, and constipation. Two months after surgery, his strength had normalized, except for slight persistent weakness in the bilateral shoulder abductors, trace weakness in the hip flexors, and a slight Trendelenburg gait. He was able to rise from a chair without using his arms and no longer required a cane for ambulation.

The patient underwent adjuvant radiation therapy after 2-month surgical follow-up with 5000-cGy radiation treatment to the left axillary region. Six months following primary definitive surgery and 4 months following adjuvant radiation therapy, he reported a 95% subjective return of physical strength. The patient was able to return to near-baseline physical activity. He continued to deny symptoms of dry mouth, incontinence, or constipation. Objectively, he had no focal neurologic deficits or weakness; no evidence of new skin lesions or lymphadenopathy was noted.

Comment

MCC vs SCLC
Merkel cell carcinoma is classified as a type of EPSCC. The histologic appearance of MCC is indistinguishable from SCLC. Both tumors are composed of uniform sheets of small round cells with a high nucleus to cytoplasm ratio, and both can express neuroendocrine markers, such as neuron-specific enolase, chromogranin A, and synaptophysin.⁹ Immunohistochemical positivity for CK20 and neurofilaments in combination with negative staining for thyroid transcription factor 1 and CK7 effectively differentiate MCC from SCLC.⁹ In addition, MCC often displays CK20 positivity in a perinuclear dotlike or punctate pattern, which is characteristic of this tumor.^3,9,10 Negative immunohistochemical markers for B cells (CD20) and T cells (CD3) are important in excluding lymphoma.

LEMS Diagnosis
Lambert-Eaton myasthenic syndrome is a paraneoplastic or autoimmune disorder involving the neuromuscular junction. Autoantibodies to VGCC impair calcium influx into the presynaptic terminal, resulting in marked reduction of acetylcholine release into the synaptic cleft. The reduction in acetylcholine activity impairs production of muscle fiber action potentials, resulting in clinical weakness. The diagnosis of LEMS rests on clinical presentation, positive serology, and confirmatory neurophysiologic testing by NCS. Clinically, patients present with proximal weakness, hyporeflexia or areflexia, and autonomic dysfunction. Antibodies to P/Q-type VGCCs are found in 85% to 90% of cases of LEMS and are thought to play a direct causative role in the development of weakness.¹¹ The finding of postexercise facilitation on motor NCS is the neurophysiologic hallmark and is highly specific for the diagnosis.

Approximately 50% to 60% of patients who present with LEMS have an underlying tumor, the vast majority of which are SCLC.¹¹ There are a few reports of LEMS associated with other malignancies, including lymphoma; thymoma; neuroblastoma; and carcinoma of the breast, stomach, prostate, bladder, kidney, and gallbladder.¹² Patients with nontumor or autoimmune LEMS tend to be younger, and there is no male predominance, as there is in paraneoplastic LEMS.¹³ Given the risk of underlying malignancy in LEMS, Titulaer et al¹⁴ proposed a screening protocol for patients presenting with LEMS, recommending initial primary screening using CT of the chest. If the CT scan is negative, total-body fludeoxyglucose positron emission tomography should be performed to assess for fludeoxyglucose avid lesions. If both initial studies are negative, routine follow-up with CT of the chest at 6-month intervals for a minimum of 2 to 4 years after the initial diagnosis of LEMS was recommended. An exception to this protocol was suggested to allow consideration to stop screening after the first 6-month follow-up chest CT for patients younger than 45 years who have never smoked and who have an HLA 8.1 haplotype for which nontumor LEMS would be a more probable diagnosis.¹⁴

In addition to a screening protocol, a validated prediction tool, the Dutch-English LEMS Tumor Association prediction score, was developed. It uses common signs and symptoms of LEMS and risk factors for SCLC to help guide the need for further screening.¹⁵

Paraneoplastic Syndromes Associated With MCC
Other paraneoplastic syndromes have been reported in association with MCC. A patient with brainstem encephalitis associated with MCC was reported in a trial of a novel immunotherapy for paraneoplastic neurologic syndromes.^16,17 A syndrome of inappropriate antidiuretic hormone (SIADH) secretion was reported in a patient with N-type calcium channel antibodies.¹⁸ Two cases of paraneoplastic cerebellar degeneration have been reported; the first was associated with a novel 70-kD antibody,¹⁹ and the second was associated with the P/Q-type VGCC antibody.²⁰ Anti-Hu antibodies have been found in a handful of reports of neurologic deterioration in patients with MCC. Hocar et al²¹ reported a severe necrotizing myopathy; Greenlee et al²² described a syndrome of progressive sensorimotor and autonomic neuropathy with encephalopathy; and Lopez et al²³ described a constellation of vision changes, gait imbalance, and proximal weakness. Support for a pathophysiologic connection among these 3 cases is suggested by the finding of Hu antigen expression by MCC in 2 studies.^24,25 Because MCC can present with occult lymph node involvement in the absence of primary cutaneous findings,³ there are more cases of paraneoplastic neurologic syndromes that were not recognized.

Extrapulmonary small cell carcinomas such as MCC are morphologically indistinguishable from their pulmonary counterparts and have been reported in most anatomic regions of the body, including gynecologic organs (eg, ovaries, cervix), genitourinary organs (eg, bladder, prostate), the gastrointestinal tract (eg, esophagus), skin (eg, MCC), and the head and neck region. Extrapulmonary small cell carcinoma is a rare entity, with the most common form found in the gynecologic tract, representing only 2% of gynecologic malignancies.²⁶

Paraneoplastic syndromes of EPSCC are rare given the paucity of the malignancy. Several case reports discuss findings of SIADH in EPSCC of the cervix, as well as hypercalcemia, polyneuropathy, Cushing syndrome, limbic encephalitis, and peripheral neuropathy in EPSCC of the prostate.^27,28 In contrast, SCLC has long been associated with paraneoplastic syndromes. Numerous case reports have been published describing SCLC-associated paraneoplastic syndromes to include hypercalcemia, Cushing syndrome, SIADH, vasoactive peptide production, cerebellar degeneration, limbic encephalitis, visceral plexopathy, autonomic dysfunction, and LEMS.²⁹ As more cases of EPSCC with paraneoplastic syndromes are identified and reported, we might gain a better understanding of this interesting phenomenon.

Conclusion

Merkel cell carcinoma is an aggressive neuroendocrine malignancy associated with paraneoplastic neurologic syndromes, including LEMS. A thorough search for an underlying malignancy is highly recommended in patients with diagnosed LEMS without clear cause. Early identification and treatment of the primary tumor can lead to improvement of neurologic symptoms.

We present a case of LEMS with no clearly identifiable cause on presentation with later diagnosis of metastatic MCC of unknown primary origin. After surgical excision of affected lymph nodes and adjuvant radiation therapy, the patient had near-complete resolution of LEMS symptoms at 6-month follow-up, without additional findings of lymphadenopathy or skin lesions. Although this patient is not undergoing routine surveillance imaging to monitor for recurrence of MCC, a chest CT or positron emission tomography–CT for secondary screening would be considered if the patient experienced clinical symptoms consistent with LEMS.

In cases of LEMS without pulmonary malignancy, we recommend considering MCC in the differential diagnosis during the workup of an underlying malignancy

Merkel cell carcinoma (MCC) is an aggressive neuroendocrine malignancy of the skin that is thought to arise from neural crest cells. It has an estimated annual incidence of 0.6 per 100,000 individuals, typically occurs in the elderly population, and is most common in white males.¹ The tumor presents as a rapidly growing, violaceous nodule in sun-exposed areas of the skin; early in the course, it can be mistaken for a benign entity such as an epidermal cyst.² Merkel cell carcinoma has a propensity to spread to regional lymph nodes, and in some cases, it occurs in the absence of skin findings.³ Histologically, MCC is nearly indistinguishable from small cell lung carcinoma (SCLC).⁴ The overall prognosis for patients with MCC is poor and largely dependent on the stage at diagnosis. Patients with regional and distant metastases have a 5-year survival rate of 26% to 42% and 18%, respectively.³

Lambert-Eaton myasthenic syndrome (LEMS) is a paraneoplastic or autoimmune disorder of the neuromuscular junction that is found in 3% of cases of SCLC.⁴ Reported cases of LEMS in patients with MCC are exceedingly rare.^5-8 We provide a full report and longitudinal clinical follow-up of a case that was briefly discussed by Simmons et al,⁸ and we review the literature regarding paraneoplastic syndromes associated with MCC and other extrapulmonary small cell carcinomas (EPSCCs).

Case Report

A 63-year-old man was evaluated in the neurology clinic due to difficulty walking, climbing stairs, and performing push-ups over the last month. Prior to the onset of symptoms, he was otherwise healthy, walking 3 miles daily; however, at presentation he required use of a cane. Leg weakness worsened as the day progressed. In addition, he reported constipation, urinary urgency, dry mouth, mild dysphagia, reduced sensation below the knees, and a nasal quality in his speech. He had no ptosis, diplopia, dysarthria, muscle cramps, myalgia, or facial weakness. He denied fevers, chills, and night sweats but did admit to an unintentional 10- to 15-lb weight loss over the preceding few months.

The neurologic examination revealed mild proximal upper extremity weakness in the bilateral shoulder abductors, infraspinatus, hip extensors, and hip flexors (Medical Research Council muscle scale grade 4). All deep tendon reflexes, except the Achilles reflex, were present. Despite subjective sensory concerns, objective examination of all sensory modalities was normal. Cranial nerve examination was normal, except for a slight nasal quality to his voice.

A qualitative assay was positive for the presence of P/Q-type voltage-gated calcium channel (VGCC) antibodies. Other laboratory studies were within reference range, including acetylcholine-receptor antibodies (blocking, binding, and modulating) and muscle-specific kinase antibodies.

Lumbar and cervical spine magnetic resonance imaging revealed multilevel neuroforaminal stenosis without spinal canal stenosis or myelopathy. Computed tomography (CT) of the chest was notable for 2 pathologically enlarged lymph nodes in the left axilla and no evidence of primary pulmonary malignancy. Nerve-conduction studies (NCSs) in conjunction with other clinical findings were consistent with the diagnosis of LEMS.

Ultrasound-guided biopsy of the enlarged axillary lymph nodes demonstrated sheets and nests of small round blue tumor cells with minimal cytoplasm, high mitotic rate, and foci of necrosis (Figure 1). The tumor cells were positive for pancytokeratin (Lu-5) and cytokeratin (CK) 20 in a perinuclear dotlike pattern (Figure 2), as well as for the neuroendocrine markers synaptophysin (Figure 3), chromogranin A, and CD56. The tumor cells showed no immunoreactivity for CK7, thyroid transcription factor 1, CD3, CD5, or CD20. Flow cytometry demonstrated low cellularity, low specimen viability, and no evidence of an abnormal B-cell population. These findings were consistent with the diagnosis of MCC.

The patient underwent surgical excision of the involved lymph nodes. Four weeks after surgery, he reported dramatic improvement in strength, with complete resolution of the nasal speech, dysphagia, dry mouth, urinary retention, and constipation. Two months after surgery, his strength had normalized, except for slight persistent weakness in the bilateral shoulder abductors, trace weakness in the hip flexors, and a slight Trendelenburg gait. He was able to rise from a chair without using his arms and no longer required a cane for ambulation.

The patient underwent adjuvant radiation therapy after 2-month surgical follow-up with 5000-cGy radiation treatment to the left axillary region. Six months following primary definitive surgery and 4 months following adjuvant radiation therapy, he reported a 95% subjective return of physical strength. The patient was able to return to near-baseline physical activity. He continued to deny symptoms of dry mouth, incontinence, or constipation. Objectively, he had no focal neurologic deficits or weakness; no evidence of new skin lesions or lymphadenopathy was noted.

Comment

MCC vs SCLC
Merkel cell carcinoma is classified as a type of EPSCC. The histologic appearance of MCC is indistinguishable from SCLC. Both tumors are composed of uniform sheets of small round cells with a high nucleus to cytoplasm ratio, and both can express neuroendocrine markers, such as neuron-specific enolase, chromogranin A, and synaptophysin.⁹ Immunohistochemical positivity for CK20 and neurofilaments in combination with negative staining for thyroid transcription factor 1 and CK7 effectively differentiate MCC from SCLC.⁹ In addition, MCC often displays CK20 positivity in a perinuclear dotlike or punctate pattern, which is characteristic of this tumor.^3,9,10 Negative immunohistochemical markers for B cells (CD20) and T cells (CD3) are important in excluding lymphoma.

LEMS Diagnosis
Lambert-Eaton myasthenic syndrome is a paraneoplastic or autoimmune disorder involving the neuromuscular junction. Autoantibodies to VGCC impair calcium influx into the presynaptic terminal, resulting in marked reduction of acetylcholine release into the synaptic cleft. The reduction in acetylcholine activity impairs production of muscle fiber action potentials, resulting in clinical weakness. The diagnosis of LEMS rests on clinical presentation, positive serology, and confirmatory neurophysiologic testing by NCS. Clinically, patients present with proximal weakness, hyporeflexia or areflexia, and autonomic dysfunction. Antibodies to P/Q-type VGCCs are found in 85% to 90% of cases of LEMS and are thought to play a direct causative role in the development of weakness.¹¹ The finding of postexercise facilitation on motor NCS is the neurophysiologic hallmark and is highly specific for the diagnosis.

Approximately 50% to 60% of patients who present with LEMS have an underlying tumor, the vast majority of which are SCLC.¹¹ There are a few reports of LEMS associated with other malignancies, including lymphoma; thymoma; neuroblastoma; and carcinoma of the breast, stomach, prostate, bladder, kidney, and gallbladder.¹² Patients with nontumor or autoimmune LEMS tend to be younger, and there is no male predominance, as there is in paraneoplastic LEMS.¹³ Given the risk of underlying malignancy in LEMS, Titulaer et al¹⁴ proposed a screening protocol for patients presenting with LEMS, recommending initial primary screening using CT of the chest. If the CT scan is negative, total-body fludeoxyglucose positron emission tomography should be performed to assess for fludeoxyglucose avid lesions. If both initial studies are negative, routine follow-up with CT of the chest at 6-month intervals for a minimum of 2 to 4 years after the initial diagnosis of LEMS was recommended. An exception to this protocol was suggested to allow consideration to stop screening after the first 6-month follow-up chest CT for patients younger than 45 years who have never smoked and who have an HLA 8.1 haplotype for which nontumor LEMS would be a more probable diagnosis.¹⁴

In addition to a screening protocol, a validated prediction tool, the Dutch-English LEMS Tumor Association prediction score, was developed. It uses common signs and symptoms of LEMS and risk factors for SCLC to help guide the need for further screening.¹⁵

Paraneoplastic Syndromes Associated With MCC
Other paraneoplastic syndromes have been reported in association with MCC. A patient with brainstem encephalitis associated with MCC was reported in a trial of a novel immunotherapy for paraneoplastic neurologic syndromes.^16,17 A syndrome of inappropriate antidiuretic hormone (SIADH) secretion was reported in a patient with N-type calcium channel antibodies.¹⁸ Two cases of paraneoplastic cerebellar degeneration have been reported; the first was associated with a novel 70-kD antibody,¹⁹ and the second was associated with the P/Q-type VGCC antibody.²⁰ Anti-Hu antibodies have been found in a handful of reports of neurologic deterioration in patients with MCC. Hocar et al²¹ reported a severe necrotizing myopathy; Greenlee et al²² described a syndrome of progressive sensorimotor and autonomic neuropathy with encephalopathy; and Lopez et al²³ described a constellation of vision changes, gait imbalance, and proximal weakness. Support for a pathophysiologic connection among these 3 cases is suggested by the finding of Hu antigen expression by MCC in 2 studies.^24,25 Because MCC can present with occult lymph node involvement in the absence of primary cutaneous findings,³ there are more cases of paraneoplastic neurologic syndromes that were not recognized.

Extrapulmonary small cell carcinomas such as MCC are morphologically indistinguishable from their pulmonary counterparts and have been reported in most anatomic regions of the body, including gynecologic organs (eg, ovaries, cervix), genitourinary organs (eg, bladder, prostate), the gastrointestinal tract (eg, esophagus), skin (eg, MCC), and the head and neck region. Extrapulmonary small cell carcinoma is a rare entity, with the most common form found in the gynecologic tract, representing only 2% of gynecologic malignancies.²⁶

Paraneoplastic syndromes of EPSCC are rare given the paucity of the malignancy. Several case reports discuss findings of SIADH in EPSCC of the cervix, as well as hypercalcemia, polyneuropathy, Cushing syndrome, limbic encephalitis, and peripheral neuropathy in EPSCC of the prostate.^27,28 In contrast, SCLC has long been associated with paraneoplastic syndromes. Numerous case reports have been published describing SCLC-associated paraneoplastic syndromes to include hypercalcemia, Cushing syndrome, SIADH, vasoactive peptide production, cerebellar degeneration, limbic encephalitis, visceral plexopathy, autonomic dysfunction, and LEMS.²⁹ As more cases of EPSCC with paraneoplastic syndromes are identified and reported, we might gain a better understanding of this interesting phenomenon.

Conclusion

Merkel cell carcinoma is an aggressive neuroendocrine malignancy associated with paraneoplastic neurologic syndromes, including LEMS. A thorough search for an underlying malignancy is highly recommended in patients with diagnosed LEMS without clear cause. Early identification and treatment of the primary tumor can lead to improvement of neurologic symptoms.

We present a case of LEMS with no clearly identifiable cause on presentation with later diagnosis of metastatic MCC of unknown primary origin. After surgical excision of affected lymph nodes and adjuvant radiation therapy, the patient had near-complete resolution of LEMS symptoms at 6-month follow-up, without additional findings of lymphadenopathy or skin lesions. Although this patient is not undergoing routine surveillance imaging to monitor for recurrence of MCC, a chest CT or positron emission tomography–CT for secondary screening would be considered if the patient experienced clinical symptoms consistent with LEMS.

In cases of LEMS without pulmonary malignancy, we recommend considering MCC in the differential diagnosis during the workup of an underlying malignancy

To the Editor:

A 56-year-old white woman with a history of melanoma and hypertension presented for evaluation of progressive hair loss of more than 1 year’s duration with associated pruritis. Scalp examination revealed diffuse erythema and scarring alopecia of the bilateral parietal and temporal regions. Physical examination also revealed nonscarring alopecia of the bilateral axillae, with associated thinning of the pubic hair, eyebrows, and eyelashes, as well as keratosis pilaris on the upper arms. Biopsy of the parietal scalp revealed mild scarring alopecia with isthmic fibroplasia consistent with early lichen planopilaris (LPP)(Figure). These histologic features combined with the patient’s clinical presentation were consistent with a diagnosis of Graham-Little-Piccardi-Lassueur syndrome (GLPL).

Graham-Little-Piccardi-Lassueur syndrome was first described by Piccardi in 1913.A second case was then described by Graham-Little in 1915 in a patient referred by Lassueur, resulting in the name it bears today.^1,2 The condition presents most commonly in middle-aged white women and is characterized by a triad of cicatricial alopecia of the scalp, nonscarring alopecia of the axillae and/or groin, and a rough follicular eruption on the body and/or scalp. Symptoms may not be present simultaneously. In GLPL, scarring alopecia of the scalp often precedes follicular eruptions of the trunk, arms, and legs by as much as years,² and the inverse also has been reported.¹ The inflammatory lesions of the scalp eventually resolve spontaneously, but the hair loss is by definition irreversible.

This rare condition is considered one of the 3 clinical variants of LPP. Other variants include classic LPP, also known as follicular lichen planus, and frontal fibrosing alopecia.³ More recently, fibrosing alopecia in a pattern distribution has gained some popularity as a fourth variant of LPP.⁴ All variants of LPP, including GLPL, result in a scarring alopecia. The classic scalp finding is an erythematous to violaceous, perifollicular, hyperkeratotic scale at the base of the terminal hairs. The population of inflamed follicles spreads outward, leaving behind a round to oval, central, atrophic scar that often is devoid of follicles. Few hairs may persist within zones of alopecia at presentation; however, these hairs are affected by inflammation and also will likely shed. A hair pull test will be positive at the margins during active disease, consisting of mostly anagen hairs on trichogram examination.^1,5 Patients may develop only a single foci of hair loss, but much more commonly, a patchy multifocal alopecia is noted.⁶ Sites often will coalesce. Onset of scalp alopecia may be insidious or fulminant.

The nonscarring alopecia of the axillae and groin may be described as subtle thinning to complete hair loss with no signs of atrophy or inflammation. Although not commonly reported, a case of nonscarring alopecia located on the shoulders has been seen.⁷

The follicular eruption that can be present on the trunk, arms, or legs in GLPL is most often but not limited to keratosis pilaris, as was seen in our patient. One reported case also described lichen spinulosus as a potential variant.⁸ Lichen planopilaris is separate from lichen planus (LP) because of its selective follicular involvement vs the nonselective mucocutaneous distribution of LP. The 2 processes also are histologically distinct; however, estimations have shown that more than 50% of patients with GLPL experience at least 1 episode of mucosal or cutaneous LP in their lifetime.⁹ Rarely, coexistence of GLPL and LP lesions has been described. One reported case of GLPL and concomitant hypertrophic LP could represent a severe form of the disease.⁹ Additionally, lichen planus pigmentosus, an uncommon variant of LP characterized by hyperpigmented brown macules in sun-exposed areas and flexural folds, was identified in a case report of an Asian woman with GLPL.¹⁰

As a general rule, the variants of LPP most commonly are seen in postmenopausal women aged 40 to 60 years; however, rare cases in a child and a teenager have been reported.¹¹ The GLPL variant of LPP is reported up to 4 times more frequently in females.⁵ Pruritus and pain are inconsistent findings, and there are no systemic signs of illness. A case of androgen insensitivity syndrome associated with GLPL suggested a potential influence of hormones in LPP.¹² Stress, vitamin A deficiency, and autoimmunity also have been proposed as triggers of GLPL.¹³ Furthermore, familial GLPL was described in a mother and daughter, though the association was uncertain.¹⁴ Our patient had no relevant family history.

Workups to reveal the etiology of GLPL have been inconclusive. Reports of laboratory testing including complete blood cell count, basic metabolic panel, liver function tests, testosterone and dehydroepiandrosterone levels, and chest radiograph have been normal.² Additional workup for viral triggers also has been negative.¹⁵ A case series of 29 patients with LPP and its variants, including GLPL, revealed positive antinuclear antibodies in 10% of patients and a thyroid disorder in 24% of patients, with Hashimoto thyroiditis being the most prevalent in 7% of cases.¹⁶ There may be a strong association between the comorbidities of thyroid dysfunction and GLPL, as documented in other studies.^10,17 A case-control study by Mesinkovska et al¹⁷ revealed a considerable increase in the prevalence of thyroid gland disease among patients with LPP vs controls. Human leukocyte antigen DR1 was found in a familial case of GLPL,⁴ and a case of GLPL following hepatitis B vaccination also has been described.¹⁸

Graham-Little-Piccardi-Lassueur syndrome most likely is a T-cell mediated autoimmune condition associated with one or multiple unknown keratinocyte antigens. Autoantibodies to the inner centromere protein were identified in a case that was positive on direct immunofluorescence, which may provide more insight into the disease pathophysiology.¹³ Interestingly, a study comparing the concentrations of inflammatory cells in LPP and traction alopecia found an elevation in the ratio of Langerhans cells to T lymphocytes within the follicular inflammatory infiltrate of LPP.¹⁹

Because the number of patients with GLPL is so few, therapy should mirror advances being made in treatments for other variants of LPP. More recent studies of LPP treatment with hydroxychloroquine showed opposing results, though the safety profile of this agent makes it an enticing treatment option.^22,23 Tetracyclines showed improvement in 4 of 15 (26.7%) patients in a retrospective study by Spencer et al.²⁴ Another retrospective study showed promising results with the potent 5-alpha reductase inhibitor dutasteride with 7 of 10 (70%) postmenopausal patients reporting stabilization over a mean duration of 28 months with no reported side effects.²⁵ Antimalarial medications also have been implemented as adjunct therapies with mixed results.⁵ A case of a 26-year-old man with GLPL from South India showed systemic disease improvement following treatment with pulsed systemic steroids, isotretinoin, and anxiolytics.⁷ Chloroquine phosphate at a daily dose of 150 mg for 3 to 9 months yielded a transient response in one postmenopausal patient with frontal fibrosing alopecia.⁶ Stabilization of hair loss was achieved with a combination of hydroxychloroquine and doxycycline in a woman with GLPL who was previously unresponsive to tacrolimus ointment.¹⁰ Thalidomide showed early promise in an isolated report claiming successful treatment of LPP,²⁶ but there is contradictory evidence, as thalidomide showed no benefit in a series of 4 patients with LPP.²⁷

Peroxisome proliferator–activated receptor gamma (PPAR-γ), a transcription factor that regulates genes, is downregulated in LPP.²⁸ Deletion of PPAR-γ within follicular stem cells in mice results in a phenotype similar to cicatricial alopecia. Data have supported the role of PPAR-γ in maintaining the pilosebaceous unit. A case report of pioglitazone (PPAR-γ agonist) therapy used at 15 mg daily for 8 months was successful in treating a patient with LPP.²⁸ Further investigation must be conducted to evaluate these treatments since early attenuation of the disease process is crucial to the reduction of permanent hair loss.

Advances in the early recognition and successful treatment of GLPL are dependent on continued research in all variants of LPP. Randomized controlled trials are necessary to establish standard of care. Further studies should target the association of GLPL and other autoimmune phenomena. Moreover, research into the etiology will provide direction in understanding disease progression and outcome.

To the Editor:

A 56-year-old white woman with a history of melanoma and hypertension presented for evaluation of progressive hair loss of more than 1 year’s duration with associated pruritis. Scalp examination revealed diffuse erythema and scarring alopecia of the bilateral parietal and temporal regions. Physical examination also revealed nonscarring alopecia of the bilateral axillae, with associated thinning of the pubic hair, eyebrows, and eyelashes, as well as keratosis pilaris on the upper arms. Biopsy of the parietal scalp revealed mild scarring alopecia with isthmic fibroplasia consistent with early lichen planopilaris (LPP)(Figure). These histologic features combined with the patient’s clinical presentation were consistent with a diagnosis of Graham-Little-Piccardi-Lassueur syndrome (GLPL).

Graham-Little-Piccardi-Lassueur syndrome was first described by Piccardi in 1913.A second case was then described by Graham-Little in 1915 in a patient referred by Lassueur, resulting in the name it bears today.^1,2 The condition presents most commonly in middle-aged white women and is characterized by a triad of cicatricial alopecia of the scalp, nonscarring alopecia of the axillae and/or groin, and a rough follicular eruption on the body and/or scalp. Symptoms may not be present simultaneously. In GLPL, scarring alopecia of the scalp often precedes follicular eruptions of the trunk, arms, and legs by as much as years,² and the inverse also has been reported.¹ The inflammatory lesions of the scalp eventually resolve spontaneously, but the hair loss is by definition irreversible.

This rare condition is considered one of the 3 clinical variants of LPP. Other variants include classic LPP, also known as follicular lichen planus, and frontal fibrosing alopecia.³ More recently, fibrosing alopecia in a pattern distribution has gained some popularity as a fourth variant of LPP.⁴ All variants of LPP, including GLPL, result in a scarring alopecia. The classic scalp finding is an erythematous to violaceous, perifollicular, hyperkeratotic scale at the base of the terminal hairs. The population of inflamed follicles spreads outward, leaving behind a round to oval, central, atrophic scar that often is devoid of follicles. Few hairs may persist within zones of alopecia at presentation; however, these hairs are affected by inflammation and also will likely shed. A hair pull test will be positive at the margins during active disease, consisting of mostly anagen hairs on trichogram examination.^1,5 Patients may develop only a single foci of hair loss, but much more commonly, a patchy multifocal alopecia is noted.⁶ Sites often will coalesce. Onset of scalp alopecia may be insidious or fulminant.

The nonscarring alopecia of the axillae and groin may be described as subtle thinning to complete hair loss with no signs of atrophy or inflammation. Although not commonly reported, a case of nonscarring alopecia located on the shoulders has been seen.⁷

The follicular eruption that can be present on the trunk, arms, or legs in GLPL is most often but not limited to keratosis pilaris, as was seen in our patient. One reported case also described lichen spinulosus as a potential variant.⁸ Lichen planopilaris is separate from lichen planus (LP) because of its selective follicular involvement vs the nonselective mucocutaneous distribution of LP. The 2 processes also are histologically distinct; however, estimations have shown that more than 50% of patients with GLPL experience at least 1 episode of mucosal or cutaneous LP in their lifetime.⁹ Rarely, coexistence of GLPL and LP lesions has been described. One reported case of GLPL and concomitant hypertrophic LP could represent a severe form of the disease.⁹ Additionally, lichen planus pigmentosus, an uncommon variant of LP characterized by hyperpigmented brown macules in sun-exposed areas and flexural folds, was identified in a case report of an Asian woman with GLPL.¹⁰

As a general rule, the variants of LPP most commonly are seen in postmenopausal women aged 40 to 60 years; however, rare cases in a child and a teenager have been reported.¹¹ The GLPL variant of LPP is reported up to 4 times more frequently in females.⁵ Pruritus and pain are inconsistent findings, and there are no systemic signs of illness. A case of androgen insensitivity syndrome associated with GLPL suggested a potential influence of hormones in LPP.¹² Stress, vitamin A deficiency, and autoimmunity also have been proposed as triggers of GLPL.¹³ Furthermore, familial GLPL was described in a mother and daughter, though the association was uncertain.¹⁴ Our patient had no relevant family history.

Workups to reveal the etiology of GLPL have been inconclusive. Reports of laboratory testing including complete blood cell count, basic metabolic panel, liver function tests, testosterone and dehydroepiandrosterone levels, and chest radiograph have been normal.² Additional workup for viral triggers also has been negative.¹⁵ A case series of 29 patients with LPP and its variants, including GLPL, revealed positive antinuclear antibodies in 10% of patients and a thyroid disorder in 24% of patients, with Hashimoto thyroiditis being the most prevalent in 7% of cases.¹⁶ There may be a strong association between the comorbidities of thyroid dysfunction and GLPL, as documented in other studies.^10,17 A case-control study by Mesinkovska et al¹⁷ revealed a considerable increase in the prevalence of thyroid gland disease among patients with LPP vs controls. Human leukocyte antigen DR1 was found in a familial case of GLPL,⁴ and a case of GLPL following hepatitis B vaccination also has been described.¹⁸

Graham-Little-Piccardi-Lassueur syndrome most likely is a T-cell mediated autoimmune condition associated with one or multiple unknown keratinocyte antigens. Autoantibodies to the inner centromere protein were identified in a case that was positive on direct immunofluorescence, which may provide more insight into the disease pathophysiology.¹³ Interestingly, a study comparing the concentrations of inflammatory cells in LPP and traction alopecia found an elevation in the ratio of Langerhans cells to T lymphocytes within the follicular inflammatory infiltrate of LPP.¹⁹

Because the number of patients with GLPL is so few, therapy should mirror advances being made in treatments for other variants of LPP. More recent studies of LPP treatment with hydroxychloroquine showed opposing results, though the safety profile of this agent makes it an enticing treatment option.^22,23 Tetracyclines showed improvement in 4 of 15 (26.7%) patients in a retrospective study by Spencer et al.²⁴ Another retrospective study showed promising results with the potent 5-alpha reductase inhibitor dutasteride with 7 of 10 (70%) postmenopausal patients reporting stabilization over a mean duration of 28 months with no reported side effects.²⁵ Antimalarial medications also have been implemented as adjunct therapies with mixed results.⁵ A case of a 26-year-old man with GLPL from South India showed systemic disease improvement following treatment with pulsed systemic steroids, isotretinoin, and anxiolytics.⁷ Chloroquine phosphate at a daily dose of 150 mg for 3 to 9 months yielded a transient response in one postmenopausal patient with frontal fibrosing alopecia.⁶ Stabilization of hair loss was achieved with a combination of hydroxychloroquine and doxycycline in a woman with GLPL who was previously unresponsive to tacrolimus ointment.¹⁰ Thalidomide showed early promise in an isolated report claiming successful treatment of LPP,²⁶ but there is contradictory evidence, as thalidomide showed no benefit in a series of 4 patients with LPP.²⁷

Peroxisome proliferator–activated receptor gamma (PPAR-γ), a transcription factor that regulates genes, is downregulated in LPP.²⁸ Deletion of PPAR-γ within follicular stem cells in mice results in a phenotype similar to cicatricial alopecia. Data have supported the role of PPAR-γ in maintaining the pilosebaceous unit. A case report of pioglitazone (PPAR-γ agonist) therapy used at 15 mg daily for 8 months was successful in treating a patient with LPP.²⁸ Further investigation must be conducted to evaluate these treatments since early attenuation of the disease process is crucial to the reduction of permanent hair loss.

Advances in the early recognition and successful treatment of GLPL are dependent on continued research in all variants of LPP. Randomized controlled trials are necessary to establish standard of care. Further studies should target the association of GLPL and other autoimmune phenomena. Moreover, research into the etiology will provide direction in understanding disease progression and outcome.

To the Editor:

A 56-year-old white woman with a history of melanoma and hypertension presented for evaluation of progressive hair loss of more than 1 year’s duration with associated pruritis. Scalp examination revealed diffuse erythema and scarring alopecia of the bilateral parietal and temporal regions. Physical examination also revealed nonscarring alopecia of the bilateral axillae, with associated thinning of the pubic hair, eyebrows, and eyelashes, as well as keratosis pilaris on the upper arms. Biopsy of the parietal scalp revealed mild scarring alopecia with isthmic fibroplasia consistent with early lichen planopilaris (LPP)(Figure). These histologic features combined with the patient’s clinical presentation were consistent with a diagnosis of Graham-Little-Piccardi-Lassueur syndrome (GLPL).

Graham-Little-Piccardi-Lassueur syndrome was first described by Piccardi in 1913.A second case was then described by Graham-Little in 1915 in a patient referred by Lassueur, resulting in the name it bears today.^1,2 The condition presents most commonly in middle-aged white women and is characterized by a triad of cicatricial alopecia of the scalp, nonscarring alopecia of the axillae and/or groin, and a rough follicular eruption on the body and/or scalp. Symptoms may not be present simultaneously. In GLPL, scarring alopecia of the scalp often precedes follicular eruptions of the trunk, arms, and legs by as much as years,² and the inverse also has been reported.¹ The inflammatory lesions of the scalp eventually resolve spontaneously, but the hair loss is by definition irreversible.

This rare condition is considered one of the 3 clinical variants of LPP. Other variants include classic LPP, also known as follicular lichen planus, and frontal fibrosing alopecia.³ More recently, fibrosing alopecia in a pattern distribution has gained some popularity as a fourth variant of LPP.⁴ All variants of LPP, including GLPL, result in a scarring alopecia. The classic scalp finding is an erythematous to violaceous, perifollicular, hyperkeratotic scale at the base of the terminal hairs. The population of inflamed follicles spreads outward, leaving behind a round to oval, central, atrophic scar that often is devoid of follicles. Few hairs may persist within zones of alopecia at presentation; however, these hairs are affected by inflammation and also will likely shed. A hair pull test will be positive at the margins during active disease, consisting of mostly anagen hairs on trichogram examination.^1,5 Patients may develop only a single foci of hair loss, but much more commonly, a patchy multifocal alopecia is noted.⁶ Sites often will coalesce. Onset of scalp alopecia may be insidious or fulminant.

The nonscarring alopecia of the axillae and groin may be described as subtle thinning to complete hair loss with no signs of atrophy or inflammation. Although not commonly reported, a case of nonscarring alopecia located on the shoulders has been seen.⁷

The follicular eruption that can be present on the trunk, arms, or legs in GLPL is most often but not limited to keratosis pilaris, as was seen in our patient. One reported case also described lichen spinulosus as a potential variant.⁸ Lichen planopilaris is separate from lichen planus (LP) because of its selective follicular involvement vs the nonselective mucocutaneous distribution of LP. The 2 processes also are histologically distinct; however, estimations have shown that more than 50% of patients with GLPL experience at least 1 episode of mucosal or cutaneous LP in their lifetime.⁹ Rarely, coexistence of GLPL and LP lesions has been described. One reported case of GLPL and concomitant hypertrophic LP could represent a severe form of the disease.⁹ Additionally, lichen planus pigmentosus, an uncommon variant of LP characterized by hyperpigmented brown macules in sun-exposed areas and flexural folds, was identified in a case report of an Asian woman with GLPL.¹⁰

As a general rule, the variants of LPP most commonly are seen in postmenopausal women aged 40 to 60 years; however, rare cases in a child and a teenager have been reported.¹¹ The GLPL variant of LPP is reported up to 4 times more frequently in females.⁵ Pruritus and pain are inconsistent findings, and there are no systemic signs of illness. A case of androgen insensitivity syndrome associated with GLPL suggested a potential influence of hormones in LPP.¹² Stress, vitamin A deficiency, and autoimmunity also have been proposed as triggers of GLPL.¹³ Furthermore, familial GLPL was described in a mother and daughter, though the association was uncertain.¹⁴ Our patient had no relevant family history.

Workups to reveal the etiology of GLPL have been inconclusive. Reports of laboratory testing including complete blood cell count, basic metabolic panel, liver function tests, testosterone and dehydroepiandrosterone levels, and chest radiograph have been normal.² Additional workup for viral triggers also has been negative.¹⁵ A case series of 29 patients with LPP and its variants, including GLPL, revealed positive antinuclear antibodies in 10% of patients and a thyroid disorder in 24% of patients, with Hashimoto thyroiditis being the most prevalent in 7% of cases.¹⁶ There may be a strong association between the comorbidities of thyroid dysfunction and GLPL, as documented in other studies.^10,17 A case-control study by Mesinkovska et al¹⁷ revealed a considerable increase in the prevalence of thyroid gland disease among patients with LPP vs controls. Human leukocyte antigen DR1 was found in a familial case of GLPL,⁴ and a case of GLPL following hepatitis B vaccination also has been described.¹⁸

Graham-Little-Piccardi-Lassueur syndrome most likely is a T-cell mediated autoimmune condition associated with one or multiple unknown keratinocyte antigens. Autoantibodies to the inner centromere protein were identified in a case that was positive on direct immunofluorescence, which may provide more insight into the disease pathophysiology.¹³ Interestingly, a study comparing the concentrations of inflammatory cells in LPP and traction alopecia found an elevation in the ratio of Langerhans cells to T lymphocytes within the follicular inflammatory infiltrate of LPP.¹⁹

Because the number of patients with GLPL is so few, therapy should mirror advances being made in treatments for other variants of LPP. More recent studies of LPP treatment with hydroxychloroquine showed opposing results, though the safety profile of this agent makes it an enticing treatment option.^22,23 Tetracyclines showed improvement in 4 of 15 (26.7%) patients in a retrospective study by Spencer et al.²⁴ Another retrospective study showed promising results with the potent 5-alpha reductase inhibitor dutasteride with 7 of 10 (70%) postmenopausal patients reporting stabilization over a mean duration of 28 months with no reported side effects.²⁵ Antimalarial medications also have been implemented as adjunct therapies with mixed results.⁵ A case of a 26-year-old man with GLPL from South India showed systemic disease improvement following treatment with pulsed systemic steroids, isotretinoin, and anxiolytics.⁷ Chloroquine phosphate at a daily dose of 150 mg for 3 to 9 months yielded a transient response in one postmenopausal patient with frontal fibrosing alopecia.⁶ Stabilization of hair loss was achieved with a combination of hydroxychloroquine and doxycycline in a woman with GLPL who was previously unresponsive to tacrolimus ointment.¹⁰ Thalidomide showed early promise in an isolated report claiming successful treatment of LPP,²⁶ but there is contradictory evidence, as thalidomide showed no benefit in a series of 4 patients with LPP.²⁷

Peroxisome proliferator–activated receptor gamma (PPAR-γ), a transcription factor that regulates genes, is downregulated in LPP.²⁸ Deletion of PPAR-γ within follicular stem cells in mice results in a phenotype similar to cicatricial alopecia. Data have supported the role of PPAR-γ in maintaining the pilosebaceous unit. A case report of pioglitazone (PPAR-γ agonist) therapy used at 15 mg daily for 8 months was successful in treating a patient with LPP.²⁸ Further investigation must be conducted to evaluate these treatments since early attenuation of the disease process is crucial to the reduction of permanent hair loss.

Advances in the early recognition and successful treatment of GLPL are dependent on continued research in all variants of LPP. Randomized controlled trials are necessary to establish standard of care. Further studies should target the association of GLPL and other autoimmune phenomena. Moreover, research into the etiology will provide direction in understanding disease progression and outcome.