Cryptorchidism is the incomplete descent of a testicle from its origin in the renal area to it destination in the scrotum. At birth approximately 3% of males will have an undescended testis and half of these will find their way into the testicle in the first month of life. Premature infants have a much higher rate of undescended testes with 30% cryptorchidism at birth. The vast majority of these will make their way down to their proper place in the scrotum without intervention. If the undescended testicle is going to reach its destination spontaneously it will do so by one year of age.


It is important to distinguish the undescended testis from the retractile testicle which is a normal testis that involuntarily retracts out of the scrotum in the cold, with physical activity and during examination. In this case the ipsilateral hemiscrotum is normally developed and the testicle can be brought into the scrotum by milking the inguinal canal from above. No treatment is needed for retractile testes.

If by one year of age the testis has not descended it should be treated. Undescended testicles if left alone undergo changes that compromise future fertility. They also have a greatly increased chance of malignancy; estimated to be 20 to 40 times greater than that of the general population. Interestingly, the normally descended contra lateral testicle is also at increased risk of malignant transformation. Testicular torsion occurs with greater frequency in undescended testes.


If the testicle is not palpable by one year of age the child should be referred to a urologist. Most urologists will proceed with surgery to bring the testicle down into the scrotum. Some, however, prefer that HCG or a LHRH analogue be administered for a period of 4 weeks. If the testicle still has not descended then they go ahead with surgery.

Contents by Dr Íomhar O' Sullivan 19/05/2005.Reviewed by Dr ÍOS 07/01/2007. Last review Dr ÍOS 13/12/21.