What are undescended testes?
In the foetus, the testes are housed in the abdomen. During development they move down through the groin into the scrotum. This happens late in foetal development, during the eighth month of gestation.
Thirty percent of premature male babies have testes that have not descended completely. Approximately three to four percent of full-term male babies have undescended testes. However, half of all cases of undescended testes naturally correct themselves without need for surgical intervention by the age of three months; almost 80% correct themselves during the first year of life. If they are not corrected, however, the condition may lead to sterility and an increased risk of testicular cancer.
An undescended testicle differs from a retractile testis in that the latter is normal but has temporarily pulled up out of the scrotal sac into the groin area.
What causes undescended testes?
The cause of undescended testes is unknown.
Who gets undescended testes and who is at risk?
Undescended testes is one of the most common malformations in young boys and occurs in about 4% of newborn boys. Fortunately, most of these undescended testicles will descend into the scrotal sacs by the first birthday. However, if they have not descended by this time into the scrotum, further descent cannot be expected and surgical correction of the abnormality will be indicated.
Symptoms and signs of undescended testes
One or both of the testicles may be undescended, with the result that they appear to be either lopsided or missing.
How are undescended testes diagnosed?
Examination of male newborns includes checking for testes in the scrotum. In most cases, the testes will drop into place later. If the testes are concealed, they may be sited in the back wall of the abdomen in a line stretching from the kidney to the scrotum. Children with undescended testes should undergo a hormone profile, including determination of gonadotropin levels.
How are undescended testes treated?
If it has been determined that the testes will not descend naturally, surgery becomes necessary. An orchiopexy is a relatively simple procedure once the testes are located. It is usually performed on children between one and two years of age.
The procedure involves surgical maneuvering of the testicle(s) down into the scrotal sac. This requires general anaesthesia. A small groin hernia is always present and is corrected at the same time. Surgery is usually done on an outpatient basis – the child can usually go to the hospital in the morning, have the operation, and go home the same afternoon. However, he will probably have to stay overnight if he has other medical problems, such as asthma or diabetes, or if both testes need to be repaired. Following surgery, the scrotum usually appears bruised and swollen – this will clear up after a few weeks.
Non-operative treatment, such as hormone injections to stimulate testicular growth and descent into the scrotal sac have been unpredictable and generally unsuccessful up to date.
Can undescended testes be prevented?
Undescended testes are often missed at birth and the condition cannot be prevented. All boys should have a medical examination before going to school for the first time, to ascertain if the testes are correctly descended. Life-long, self-examination of testes is thereafter important to monitor for cancer.
What is the outcome of undescended testes?
If left untreated, undescended testes are associated with an increased risk of testicular cancer and sterility.
Undescended testes are twice as likely to develop cancer compared with normal testes.
An undescended testis that remains outside the scrotum during childhood could also result in impaired or abnormal testicular development – ultimately resulting in infertility.
In addition, most undescended testicles are associated with congenital hernia, and are more prone to injuries than a testicle located within the scrotal sac.
(Reviewed by Dr Pieter J. le Roux)