Ultrasonic localization of a non-palpable testis tumor.

A young man was found to have a retroperitoneal seminoma and normal testicles by palpation. Initial diagnosis was an extratesticular primary germ cell tumor until ultrasound examination detected a lesion in the left testicle. A left radical orchiectomy was done and a seminoma of the testicle was found. We recommend ultrasound examination of the testicles to demonstrate occult testicular tumors when faced with the possibility of an extratesticular primary germ cell tumor.