Undescended testis is a condition where the child is found to have a testis to be absent from the scrotum at the time of birth. The normal testicular development happens inside the abdomen and the testicle moves from the abdomen downward to the groin in the inguinal canal and comes to the scrotum just before birth. Therefore through the route of the testicular descent, the descent can be arrested at any stage and results in the in the undescended testis with various positions of the undescended testicle. So this is classified according to the position of the testis which includes: abdominal testis, inguinal testis, pre-scrotal or pre-pubic testis and the normal testicle position of scrotal testis.
How common is undescended testis?
At one year of age nearly 1% of full term male infants may have undescended testis. This is the most common congenital anomaly affecting the genitalia of the newborn male. If the testicle is palpable though undescended, it is called palpable testis. If it is not palpable it is called non-palpable testis as the clinical management will be influenced by whether the testicle is palpable or not. If the testicle is palpable then further management will depend on the location of the testis.
What is the initial management of undescended testis?
When the newborn is diagnosed with undescended testis, it is entirely reasonable to wait and see if there is further descent of testis for up to six to nine months. If there is no decent of testis by nine months, the testicle is unlikely to descent further and this patient would need a referral to a specialist (either a urologist or a paediatric surgeon). Of course in the presence of an inguinal hernia, a referral would not be necessary.
What is the treatment for undescended testis?
If the testis has not descended by one year of age, there is no benefit in further waiting. There is evidence that the histological deterioration in seminal vesicles occur after eighteen months of age and there fore the ideal time to operation is between twelve and eighteen months. This is likely to preserve the sperm producing function of the testis. If the testis is not palpable then the position of the testicle needs to be ascertained. This is done possibly by laparoscopy to assess the position of the testicle to determine if it is intra-abdominal or in the groin. Depending on the position of the testis, further procedures will be necessary.
What is the logic to using medical treatment?
There is logic to using medical therapy with human chorionic gonadotrophin (hCG) or gonadotrophin-releasing hormone (GnRH) can be used. This is based on the hormone dependence of the testicle at descent and the maximum success rate of such treatment is only 20%.
What is the prognosis after surgical treatment for undescended testis?
Boys with one undescended testis have a slightly lower fertility rate, though they have the same paternity rate (ability to become a father) as the boys with both descended testicles.
Boys with undescended testis have 20 fold higher risk of developing testicular cancer. A risk which is not influenced by any kind of treatment. Therefore screening during and after puberty may be recommended. The best form of screening is self examination and child as they become adults should be taught about the importance of testicular self examination. Though there is a 20 fold higher risk as opposed to the normal population, testicular cancer is a rare disease.