UNDESCENDED TESTIS

Undescended testicle, also called cryptorchidism, is a common condition in which one of the testicles is not located within the scrotum. During the eighth month of the mother's pregnancy, the baby's testes migrate from the abdomen, through the groin, and into the pouch that contains the testes (scrotum).

An undescended testicle may be located in the abdominal cavity, in the passageway in the groin (inguinal canal), or in an ectopic location (e.g., superficial pouch in the groin, perineum, upper thigh). This condition is usually present at birth (congenital) and is associated with sterility and an increased risk for testicular cancer if not corrected.

Undescended testicle may occur in approximately 30% of premature males and 3% of full term male infants. In 80% of cases, the undescended testicle migrates into the correct position without intervention during the first year. The condition may involve both testicles in about 10% of cases.

The cause of undescended testicle is not known. If the father or brother ad the conditionm, there is an increased risk. Other risk factors include the following:

* Low birth weight (less than 2500 g)
* Maternal exposure to estrogen during the first trimester
* Multiple birth (e.g., twin, triplet)
* Premature birth (before 37 weeks gestation)
* Small size for gestational age

Diagnosis of this condition is made through physical examination at birth to locate the testis. If one testicle is undescended, the scrotum appears unbalanced. If the undescended testis is felt (palpable) it may not have descended fully, may have descended into a location other than the scrotum (ectopic), or may move in and out of the scrotum through muscle contraction (retractile).

If the testis is non palpable, it may be located within the abdomen or may be absent (occurs in 5% of cases). A congenitally absent testicle may result from an abnormality in testicular blood vessels or testicular torsion in utero.

In humans, the scrotal location of the testicles keeps them cooler than the core body temperature which is important for the development of the testicle as well as for production of normal sperm. Studies have shown that there is an increased risk of infertility in men with a history of undescended testicles. Relocating the testicle into the scrotum may decrease the risk of fertility problems, particularly if done at an early age.

There are other advantages to a location within the scrotum. There is a cosmetic advantage. The scrotal testicle may be at less risk to injury than a testicle outside the scrotum. Finally, and perhaps as important as any other reason, a testicle that has not made it into the scrotum is not accessible to physical examination.

Undescended testicles are at increased risk for cancer. Testicular cancer may not occur until after age 40 years. Testicular carcinoma is highly curable, when detected early, and the best way to do this is monthly self-examination, which can only be done if the testicles are within the scrotum.

It is recommended that treatment of the undescended testicle be done before one year of age. There is evidence that early damage to the germ cells that produce sperm begins at this age.

There are two options for treatment. Injections of a hormone, HCG, several times per week over several weeks can produce descent in some children. However, the success rates have been reported to be as low as 10%. Also, the results of hormone treatment are less successful in children less than two years of age.

The most effective treatment is surgery, which can be performed as an outpatient. When a testis is felt in the groin area we usually explore the area through a small incision. Most undescended testes are associated with a hernia that must be repaired. After this is done, the testis is brought down into the scrotum and anchored in a space created in the scrotum (orchiopexy).

When a testis is not palpable on physical exam, its location must be determined. No x-rays are reliable in this regard. A diagnositic laparoscopy is done. A laparoscope through a small incision below the 'belly button' to look in the abdomen at the time of surgery. In those patients found to have testes very high in the abdomen, additional surgery is required to correct the problem. A number of children will be found to have very small abnormal gonads, removal of the gonad is done. Most of these children probably had torsion or twisting of the testis on its blood supply prior to birth that led to the small testis. When a boy is left with a single functioning testis it is recommended that it be anchored to minimize chances of losing it to torsion later in life.