Abstract
Small intestinal GIST is relatively rare disease, and is difficult to diagnose in early stage for poor symptoms. A 51-year old man was transferred from other hospital due to abdominal pain and bloody discharge getting worse. On admission, abdominal CT scan showed a large tumor with gas and fluid lesion in the pelvis. We performed an emergent surgery, having diagnosed as perforating abscess. On intra-operative findings, there was a large tumor measured 12cm in the lower abdomen with abscess, and, that was growing on the antimesenteric side of the small intestine 50cm oral side of ileocecal valve. Partial resection of the intestine was performed, but we could not resect the tumor completely because of the invasion of surrounding organs and peritoneal dissemination. On immunohistochemistry, the tumor cells were positive for c-kit and CD34. The tumor was diagnosed as small intestinal GIST with liver metastasis and peritoneal dissemination. After surgery, imatinib therapy led to marked tumor shrinkage and almost complete clinical remission. Small intestinal GIST with perforating abscess is rare; a case with which concurrent metastasis present that had got more than 5-year survival has been seldom reported in Japan.
