[Testis yolk sec tumor--a case report].

A 16-months old normal boy, a right testicular mass was discovered incidentally by his grandmother. Right inguinal orchiectomy was performed. Histological examination showed yolk sac tumor of testis. A preoperative alpha-fetoprotein level was markedly elevated at 13568.9 ng/ml, by the end of the twelve postoperative months, the serum alpha-fetoprotein levels was 118 ng/ml. The patient is doing well one-year postoperatively.