十二指腸gastrointestinal stromal tumorの1例

77 year-old male presented with prolonged melena and anemia. There was a well-defined enhancing mass in the descending portion of the duodenum that was approximately 6 cm in diameter on contrast-enhanced computed tomography (CT). Large ulcerated mass was seen in the duodenum on endoscopy. Preoperative biopsy was diagnostic for gastrointestinal stromal tumor (GIST) and partial resection of the duodenum was performed. Postoperative diagnosis was malignant GIST. Immunohistochemistry demonstrated negative S-100, negative actin, positive C-kit and partially positive CD34.