Q2. Correct answer: D. Treatment for recurrent or metastatic disease is imatinib.
This patient has a gastrointestinal stromal tumor (GIST) of the stomach. GISTs are the most common mesenchymal tumor found in the stomach. Gastric GISTs have a better prognosis than those found in the small intestine. GISTs are often found incidentally but can cause symptoms such as bleeding due to ulceration. Pathology of a GIST shows spindle cells that stain positive for CD117 and harbor KIT mutations. Malignant potential and decreased survival are associated with size more than 2 cm and high mitotic index (more than 5/50 high power field). Endoscopic ultrasound with tissue sampling is the preferred diagnostic technique. High-risk features include lobulated or irregular borders, invasion into adjacent structures and heterogeneity. Fine needle aspirate may be suboptimal, and core biopsy is an acceptable alternative. Resection is indicated for lesions that are symptomatic, size more than 2 cm or high-risk EUS features. Lesions less than 2 cm without high-risk features can be surveyed by EUS annually. Endoscopic resection might be possible for small lesions but should be done in specialized centers. Metastatic or recurrent lesions are treated with imatinib.
ASGE Standards of Practice Committee. Gastrointest Endosc. 2015 Jul;82(1):1-8.