Primary omental liposarcoma presenting with torsion: a case report.

An 83 year-old man was admitted because of abdominal pain and distention. A mass measuring 20x10 cm and associated with tenderness and guarding was palpable in the right lower abdomen. Ultrasonography and computed tomography showed a tumor with solid and multiple cystic areas. Celiac angiography showed slight tumor vascularity fed by the right gastroepiploic artery. A malignant tumor of the omentum was suspected. At laparotomy, torsion of the omental pedicle of the tumor was found. Histological examination of the resected tumor revealed characteristics of round-cell liposarcoma, which usually has a poor prognosis. The patient has been alive and well for 2 years. Primary liposarcoma of the omentum has been reported in only seven previous cases. None of these patients presented with torsion, and no report has thus far included a documented survival.