Abstract
Gastrointestinal stromal tumors (GISTs) are common mesenchymal tumors of the gastrointestinal organs, but GISTs of the lesser omentum are very rare. A 79-year-old woman presented with a small abdominal mass that on laparotomy was found to originate from the lesser omentum. The tumor was 2.5 cm in diameter and was adjacent to the lesser curvature of the stomach. The mass was completely resected. Histological examination showed spindle cells. Immunohistochemically, the tumor cells showed positivity for CD117 and CD34. The mitotic count was 2 per 50 high-power fields. From these findings, low risk extragastrointestinal stromal tumor of the lesser omentum was diagnosed. The patient's postoperative course was uneventful and has been closely observed.
