Abstract
We report a rare case of gastrointestinal stromal tumor of the colon. A 35-year-old woman admitted with lower abdominal pain under a diagnosis of peritonitis underwent emergency. Laparotomy showed a large tumor of the sigmoid colon had ruptured, necessitating sigmoidectomy. Histopathological findings showed interlacing fascicles of spindle cells with high cellularity. Immunohistochemically, tumor cells were positive for ckit and CD34 and negative for alpha-smooth muscle actiin and S-100 protein. The pathological diagnosis was malignant gastrointestinal stromal tumor, uncommitted, of the sigmoid colon. The patient is free of tumor reccurence 18 months since surgery.
