A case of testicular angiomyolipoma.

The majority of testicular tumors are germ cell tumors, which are the most prevalent solid malignancies in young adult males. Non-germ cell tumors of the testis are rare. Here, we report a case of testicular angiomyolipoma (AML). A 22-year-old male underwent left orchiectomy under a diagnosis of testicular tumor. Pathological analysis demonstrated that it was composed of adipose tissue and vasculature with foci of myomatous component. The tumor demonstrated neither cytological atypia nor widespread mitotic activity. In addition, the tumor cells showed intense expression of CD34 and smooth muscle actin, whereas HMB-45 was entirely negative. Although the true cellular origin and its clinical implications remain unknown, pathological and immunohistochemical studies strongly indicated benign testicular AML with a non-germ cell origin. To our knowledge, this is only the second case of a primary testicular AML in the published reports and the detailed pathological findings are first described in this report.