Prostate and seminal vesicle solitary fibrous tumor combined with prostate adenocarcinoma. Case report

Solitary fibrous tumor is an extremely rare fibroplastic mesenchymal neoplasm with an uncertain malignant potential and intermediate biological behavior. It is most often localized in the pleura. Extrapleural lesions of the genitourinary system, including the prostate gland and especially the seminal vesicles, occur in anecdotal cases. There are no specific clinical manifestations of tumor localized in the prostate gland; it can mimic prostate adenoma with infravesical obstruction. With the localization of the tumor in the seminal vesicles, local symptoms are more common: hematuria, dysuria, and hemospermia. The basis of medical imaging is contrast-enhanced magnetic resonance imaging and combined positron emission and X-ray computed tomography with various tracers. To confirm the diagnosis, a biopsy followed by histological and immunohistochemical examination with determination of CD34 and STAT6 expression in the tumor tissue is required. The main therapy for a solitary fibrous tumor is surgical excision with a resection margin of 1–2 cm. The article presents a unique clinical case of a primary multiple synchronous solitary fibrous tumor of the prostate and seminal vesicle combined with prostate cancer. This is the first such case described in the available Russian and international literature. Timely diagnosis of these neoplasms enables a rational approach to personalized treatment.