Solitary fibrous tumor of the urinary bladder in an 85-year-old woman: Case report and review of literature

A solitary fibrous tumor of the urinary bladder is an extremely rare type of mesenchymal tumor. We present a case of an 85-year-old woman with a large (14.5×10.7×10.1 cm) protruding intravesical mass detected by computed tomography (CT) and magnetic resonance imaging (MRI), which was proven to be a solitary fibrous tumor through histopathological examination. The clinicopathologic and radiological features are here discussed, along with a review of the published literature on this topic. Solitary fibrous tumors of the urinary bladder are more common in men (76%), with a peak incidence in people 40–60 years old. Most such tumors show heterogeneous intensity with a complete capsule. A decrease in the T2WI signal with an increase in collagen tissue content and gradual enhancement on CT/MRI images are their main features. Most such tumors are positive for CD34 under immunohistochemistry (100% in 24 available cases). The majority of tumors (88%) studied have been non-malignant and most patients (95.5%) showed favorable prognosis after a long-term follow-up.