A rare case of gastrointestinal stromal tumor in an unusual location

Abstract

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the gastrointestinal (GI) tract. They originate or differentiate toward the interstitial cells of Cajal, an integral part of the GI autonomic nervous system of the GI tract. GISTs are mostly seen arising from the muscularis mucosa or propria layer of the stomach or small intestine with just one case of gastric GIST reported arising from the serosal layer. We report the case of a 46-year-old woman who presented with progressive abdominal mass and abdominal pain. Computed tomography scan and intraoperative findings revealed a huge, well-circumscribed cystic mass arising from the anti-mesenteric border of the ileum. An impression of mesenteric desmoid tumor was made but diagnosed to be GIST on histological examination with immunohistochemistry. This report shows the importance of including GIST in the differentials when investigating serosal based tumors of the GI tract even when the radioimaging findings are inconsistent.