Paratesticular leiomyosarcoma in an elderly man.

Soft tissue tumors, both benign and malignant, of the testes are relatively uncommon. Primary leiomyosarcoma of the testis is rare, and its clinical behavior is difficult to predict. We report a case of paratesticular leiomyosarcoma in a 71-year-old man. Routine histologic examination and immunohistochemical staining were performed. The tumor was composed of interlacing fascicles of smooth muscle cells with marked nuclear pleomorphism and three to four mitoses per high power field, with few atypical mitoses. On the basis of the microscopic examination and immunohistochemical studies, the tumor was identified as a paratesticular leiomyosarcoma. The published studies on this entity are reviewed.