A Case of Small Intestinal Gastrointestinal Stromal Tumor That Required Emergency Surgery After Preoperative Diagnosis of Intra-abdominal Abscess

Abstract

The patient was a 55-year-old man who presented to our hospital with a two-day history of right lower abdominal pain and fever. CT showed a tumor in the lower abdomen measuring 15 cm in diameter with an enhancing edge, accompanied by an internal air-fluid level. Laboratory examination revealed an increase of the WBC count and serum CRP level, which led to the suspicion of an intra-abdominal abscess complicating perforated appendicitis. Emergency surgery was performed. Laparotomy revealed no abscess formation, but a well-defined tumor, about the size of a child’s head, attached to the small intestine; therefore, partial resection of the small intestine was performed. The tumor was composed of solid and cystic portions containing dark red fluid. The patient was diagnosed as a high-risk group of a small-intestinal GIST with a maximum diameter of 15 cm, that showed positive staining for c-kit, and 2 mitotic figures/50 HPF. Due to the delayed detection of small-intestinal GISTs, the growth of these tumors can cause internal necrosis and infection, with the same findings and course of progression as those of an intra-abdominal abscess.