Giant intrapelvic solitary fibrous tumor arising from mesorectum

We report a patient who had a giant pelvic solitary fibrous tumor (SFT) that was excised with the aid of aortic balloon occlusion. A 27-year-old woman was diagnosed, at another hospital, as having an inoperable intrapelvic tumor. On admission, computed tomography showed that the uterus, urinary bladder, and rectum were compressed anteriorly by a pelvic tumor with a maximum diameter of 16 cm. On magnetic resonance imaging, the tumor contained mesh-like structures showing strong intensity. Transanal needle biopsy was performed, and SFT was diagnosed by immunostaining. The tumor was supplied by feeding vessels from the inferior mesenteric artery and bilateral internal iliac arteries. Despite massive intraoperative hemorrhage, this giant tumor was excised with the help of aortic balloon occlusion. An intrapelvic SFT should be resected after careful preparation of countermeasures for hemorrhage.