Abstract
A case of solitary fibrous tumor (SFT) in the pelvic cavity is reported. A 65-year-old man was seen at our hospital because of a large left hip swelling. CT showed a round, heterogeneously enhanced, smooth-surfaced mass compressing the rectum. No invasion was detected. Colonoscopy showed that the lower rectum was compressed from the left side, but the mucosa appeared normal. Because sarcoma or GIST was suspected, a needle biopsy was performed, and the histological diagnosis was SFT. Extirpation of the tumor through an abdominosacral approach was successfully performed without injury to the rectum. Macroscopic findings of the resected specimen showed an encapsulated, grayish white, elastic soft tumor, 9.6 × 8.5 × 5.2 cm in seize. On histological examination, the tumor was composed of spindle-shaped and oval cells, which were immunohistochemically positive for CD34 and vimentin. These findings suggested a diagnosis of SFT in the pelvic space. The patient's postoperative course was uneventful, and the patient is alive without recurrence 17 months after the excision.
