Paratesticular Solitary Fibrous Tumor: A Case Report With Sonographic and Histopathologic Insights.

Solitary fibrous tumor (SFT) is a rare mesenchymal neoplasm of fibroblastic differentiation that is generally considered benign. It most commonly arises from the pleura, typically presenting as a thoracic mass. Extrapleural occurrence, particularly within the urogenital tract, such as the paratesticular region, is exceedingly rare. The histopathological characteristics of paratesticular SFTs are similar to those observed in tumors arising at other anatomical sites. We report the case of a 26-year-old man presenting with a painless, firm, and mobile paratesticular mass that had progressively enlarged over two years. The lesion was completely excised surgically without perioperative complications. Gross and histopathological examination demonstrated a well-circumscribed lesion composed of uniform spindle cells embedded in a dense collagenous stroma. Immunohistochemical analysis showed diffuse positivity for cluster of differentiation 34 (CD34). These findings supported the diagnosis of paratesticular SFT.