A Case of Solitary Fibrous Tumor of the Ileum

A 72-year-old woman admitted for a pelvic tumor cavity in November 2007 was found in abdominal computed tomography (CT) to have a 5.0×8.0 cm tumor drainaged by the superior mesenteric vein yielding a prepoperative diagnosis of gastrointestinal stromal tumor of the ileum. The tumor and ileum were resected. The tumor 9.0×7.0×6.0 cm attached to the ileal serosa, was white and yellowish white with necrosis and hemorrhaging. Histologic of findings indicated that the tumor arose from the ileal serosa. It showed a patternless proliferation of spindle cells with irregularly arranged hyalinized collagen bundles in a myxoid stroma and prominent vessels such as those in hemangiopericytoma. Tumor cells showed immunohistochemical reactivity for vimentin, CD34, CD99, and bcl-2 but were negative for c-kit. Histology indicated a solitary fibrous tumor of the ileum. The postoperative course was uneventful and the woman remains disease-free 6 months after surgery. A solitary fibrous tumor of the ileum is very rare.