Question: A 26-year-old woman was admitted with a 3-week history of progressive abdominal distension, nausea, vomiting, and tarry stool. She denied any significant past medical history or family history. Physical examination revealed mild epigastric tenderness. Laboratory tests were unremarkable except for a moderate normocytic anemia (hemoglobin, 72 g/L). Barium-meal radiographs in her local community hospital showed a large, semicircular filling defect in the antrum of the stomach (Figure A). Upper gastrointestinal endoscopy revealed a nodular lesion (Figure B).