A Case of Abscess-forming Gastrointestinal Stromal Tumor (GIST) of the Small Intestine

Abstract

A 43-year-old man presented with anorexia and fever. An abdominal CT scan revealed a 110×70 mm tumor in contact with the small bowel wall in the left common iliac artery. The tumor was diagnosed with an intra-abdominal abscess. The abscess did not respond to antibiotics, leading to continuous drainage via a placed catheter on the next day. He was getting better after drainage. A small intestine contrast examination showed barium accumulation almost coincident with the tip of the catheter, and the ulcer region was found in the jejunum near the abscess. Crohn's disease was suspected, and a small bowel ulcer was found by a double-balloon endoscopy (DBE). But there were few findings suggestive of Crohn's disease by a biopsy. On the 49th hospital day, partial resection of the small intestine including the tumor was performed for diagnosis and treatment. According to the histopathological findings, the definitive diagnosis of this tumor was a high-risk group of gastrointestinal stromal tumor (GIST) of the small intestine with abscess formation. On the 56th day after the operation, oral administration of imatinib mesylate was begun, and he is alive without recurrence for 2 years and 1 month following the operation. Small bowel GIST with intra-abdominal abscess formation is rare and we report with a review of the literature.