A Case of Multicentric Dedifferentiated Liposarcoma in the Stomach and Mesentery

Abstract

A man in his 60s was referred to our hospital for evaluation of a submucosal mass in the stomach incidentally found during upper gastrointestinal endoscopy at a regular medical checkup. An enhanced computed tomography (CT) scan showed a lobular, heterogeneously enhanced mass in the gastric fornix, and another round, heterogeneously enhanced mass was found in the mesentery. These masses showed FDG uptake on positron emission tomography CT and demonstrated low signal intensity on T1WI and heterogeneous intensity on T2WI. The patient underwent partial gastrectomy and colectomy and was diagnosed with multicentric dedifferentiated liposarcoma in the stomach and mesentery. Dedifferentiated liposarcoma is a variant of liposarcoma with a more aggressive course. It occurs most commonly in the retroperitoneum and rarely in other anatomic locations. In this report, we describe a case of dedifferentiated liposarcoma arising simultaneously from the stomach and mesentery. Multiple abdominal liposarcoma is an extremely rare entity. In dedifferentiated liposarcoma, the adipose component may not be identified on images, and preoperative diagnosis is difficult.