Dedifferentiated liposarcoma arising from the mesocolon ascendens: report of a case.

Dedifferentiated liposarcoma of the mesentery is an extremely rare tumor. A 71-year-old man with a 2-month history of abdominal distention was admitted to our department for evaluation and treatment of an abdominal mass. Computed tomography and magnetic resonance imaging revealed an 11 X 9 cm mass lesion with fat density in the upper right abdominal cavity, displacing the ascending and transverse colon ventrally. Abdominal angiography showed small feeding vessels of the tumor from the ileocolic artery and the middle colic artery. On basis of these findings, liposarcoma arising from the mesocolon ascendens was diagnosed, and complete removal of the tumor and central pancreatectomy (partial resection of the body of the pancreas) were performed. The histopathological diagnosis was dedifferentiated liposarcoma, and the patient is free from recurrence 6 months after surgery. The treatment strategy for abdominal dedifferentiated liposarcoma is surgical resection with a wide surgical margin. (J Nippon Med Sch 2012; 79: 385-390)