Abstract
A 38-year-old woman with generalized neurofibromatosis was admitted to the emergency department with complaint of pain and nontender mass in epigastrium. She had been treated in another hospital as an intra-abdominal abscess and tube drain was seen to be coming out of the centre of the mass. Later investigations and surgery revealed a large exophytic tumor arising from the posterior wall of the stomach infiltrating the transverse colon. Resection of the involved stomach and middle third of the transverse colon was done. Histology examination proved to be leiomyosarcoma positive for CD117 and S-100. Gastrointestinal stromal tumors (GISTs) in neurofibromatosis type 1 (NF1) are multiple and commonly involve the small intestine. This is a rare case of GISTs in NF1 involving the stomach and presenting as an intra-abdominal abscess.