This is a case report of embryonal rhabdomyosarcoma of the epididymal appendage in a 15-month old infant. It is a rare tumor with a good prognosis when treated promptly. The ultrasound examination showed the testicle to be enlarged but hypo-echoic in comparison to the epididymis which was infiltrated with tumor. An inflammatory mass or enlargement of a testicle demands careful diagnosis and appropriate therapy with immediate referral to a urologist if the normal clinical course deviates. Representative images are included.
