Undifferentiated sex cord-stromal tumor in a young adult.

Undifferentiated sex cord-stromal tumor in post-puberty male is extremely rare. There were only three reported cases in the literature. We reported a 19-year-old patient presented with an asymptomatic right testicular nodule with normal level of serum marker for germ cell tumor. Excisional biopsy and subsequent orchidectomy was preformed and the final pathology supported the diagnosis of undifferentiated sex cord-stromal tumor. He was then put on regular surveillance with no adjuvant therapy given. He remained disease free 18 months after the operation. A summary of the literatures and discussion on the management of this rare tumor was provided.