This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Large intestine, Subject name: Surgery
[{'content': 'Most common extra-intestinal malignancy in HNPCC: \nSelect and explain. \nA. Pancreatic carcinoma, B. Ca stomach, C. Small bowel carcinoma, D. Transitional cell carcinoma', 'role': 'user'}, {'content': 'Answer: B \nExplanation: EXTRA - INTESTINAL MALIGNANCIES IN HNPCC Endometrial (39-60%)>gastric (13-19)>ovarian (6-12%) Rare Malignancies: Small intestine, pancreatic, thyroid, transitional cell epithelium in the urinary tract (renal pelvic, ureter, bladder); brain cancers.', 'role': 'assistant'}]