Solitary fibrous tumor involving urinary bladder: a case report and literature review.

Solitary fibrous tumor (SFT) is a rare fibroblast stroma tumor involving the mediastinum and pleura. We herein describe an SFT of bladder which is extremely rare and review 29 similar cases in the last decades. We present a case of a 52-year-old male patient who suffered from urinary urgency and frequency for 12 months. Non-contrast computed tomography (CT) showed a slightly high density calcified mass with 70 mm × 61 mm in diameter. Contrast-enhanced CT demonstrated the mass was slightly enhanced. Cystoscopy revealed a huge mass with flat surface. Histopathological review of the biopsy specimens could not confirm the diagnosis. Partial cystectomy was then performed and the diagnosis of SFT was confirmed by immunohistochemistry. The patient is doing well at 12 months follow-up without recurrence and metastasis. In conclusion, the diagnosis of SFT involving bladder should combine clinical presentation and imaging features. Complete surgical resection is the primary method and long-term follow-up is necessary.