Computed tomography of gastrointestinal leiomyosarcoma.

Computed tomography (CT) was performed in 6 patients with gastrointestinal leiomyosarcoma. The characteristic CT findings were a large extraluminal mass, apparently mesenteric in location, with central areas of necrosis. These findings were present in 5 of the 6 patients. Enhancement of the rim of the tumor was seen in 2 of 3 patients who had scans before and after administration of intravenous contrast material. CT identified the site of origin of tumor in only 2 patients. The characteristic CT findings should suggest the diagnosis of gastrointestinal leiomyosarcoma.