Solitary Fibrous Tumor of the Prostate: What is the Optimal Treatment? Description of A Case and Review of the Pertinent Literature

Abstract

A solitary fibrous tumor (SFT) originating from the prostate has been rarely reported, presenting the 44th case. We evaluated a 44-year-old man who presented with a two-year history of pressure in the lower abdomen. On magnetic resonance imaging, a 48×66 mm, well-circumscribed mass was observed. 12-core prostatic needle biopsy was performed. Histological examination reported hypocellular and hypercellular areas composed of bland spindle cells arranged in a haphazard pattern. One or two mitotic figures were observed per 10 high-power-fields. Immunohistochemistry analysis showed a strong expression of CD34, STAT-6, and vimentin by tumor cells. We conducted a surveillance protocol for the patient due to the avoidance the surgery. Although there was an increase of approximately 2 cm in tumor diameter, no change was detected in tumor cellularity, number of mitosis, and other histopathological findings in complementary prostatic needle biopsy after three years of follow-up. A literature review of all prostatic SFTs was performed on histopathological features, treatment modality, and reported recurrence and progression data to identify optimal treatment. Local recurrence was reported in five (11.6%) cases and metastasis in two (4.7%) cases. Twenty-two patients underwent radical surgery with a negative margin. None of these had local recurrence and metastasis was reported in only one. Palliative surgery was reported in 18 patients, including five with local recurrence. However, six had no local recurrence or metastasis during the reported follow-up period. Careful surveillance can be conducted in informed patients if there is no malignancy in the histopathologic examination. In all other cases, surgery is strongly advised and should be radical rather than palliative.

Keywords

• solitary fibrous tumor
• prostate
• immunohistochemistry
• stat6