An unusual abdominal tumor--leiomyosarcoma of the mesentery: a case report.

We report the case of an 82-year-old woman who presented with an ill-defined mass and tenderness in the right lower quadrant of the abdomen. On computerized tomography scan, she had an irregular large bosselated mass of the mesentery located medial to the cecum and associated with multiple loops of small intestine. Preoperative differential diagnoses included leiomyosarcoma, lymphoma and gastrointestinal stromal tumor. The mesenteric mass was resected and identified as a leiomyosarcoma. This patient's tumor is typical of a mesenteric leiomyosarcoma and recurred with hepatic metastases two years after its initial removal. Such tumors usually do not become symptomatic until late in the course of disease, often after distant metastases have occurred. Mesenteric leiomyosarcomas are rare and have a reported incidence of 1: 350,000.