Giant pelvic solitary fibrous tumor obstructing intestinal and urinary tract: a case report and literature review

We are reporting a giant pelvic neoplasm, a rare solitary fibrous tumor that presented with a large bowel obstruction and bilateral ureteral obstruction because of its size and location. Preoperative diagnosis required complex pathological studies to exclude a high-grade sarcoma suspected clinically. Complete resection was required for resolution of obstructive symptoms. Prognosis for solitary fibrous tumors is usually good after complete resection. Recurrence and metastasis may be related to rare aggressive histological features, including nuclear atypia, hypercellularity, greater than four mitoses/10 high power fields, and necrosis. Because histology is not always a reliable predictor of prognosis, careful long-term follow-up is necessary for this tumor. Solitary fibrous tumors (SFTs) are rare spindle cell neoplasms most likely arising from mesenchymal cells. SFTs were originally described in the pleura, the most common site for this tumor; however, extrathoracic SFTs are seemingly diagnosed with increased frequency. We report a case of a giant pelvic SFT that required complicated clinical management.