A 60-year-old man investigated for iron deficiency anaemia has endoscopy showing a smooth submucosal mass in the gastric fundus. Biopsy shows spindle-shaped cells. Immunohistochemistry demonstrates strong positivity for CD117 (c-kit) and DOG1. Which statement about this tumour is correct?
- A It arises from interstitial cells of Cajal and metastasises chiefly to regional lymph nodes
- B First-line treatment for unresectable disease is cisplatin-based chemotherapy
- C Malignant potential correlates with tumour size and mitotic count rather than depth of invasion ✓
- D Wide local excision with extended lymphadenectomy is required for cure
Correct answer: C. Malignant potential correlates with tumour size and mitotic count rather than depth of invasion
Explanation
GISTs arise from the interstitial cells of Cajal and express c-kit (CD117); risk stratification depends on size and mitotic rate, not depth of invasion as in carcinomas. They spread mainly by blood and peritoneal seeding, and lymph node involvement is distinctly uncommon, so extended lymphadenectomy adds nothing; a complete local excision suffices. Unresectable or metastatic GIST is treated with the tyrosine kinase inhibitor imatinib mesylate, not cytotoxic chemotherapy.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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