Undescended Testes (Cryptorchidism)

Undescended testes is a congenital disorder also known as cryptorchidism. One or both testes remain in the abdomen, in the inguinal canal, or at the external ring instead of descending into the scrotum. The disorder may occur bilaterally but usually affects only the right testis; it may be categorized as true or ectopic. True undescended testes remain along the path of normal descent; ectopic testes deviate from that path.

Because the testes normally descend into the scrotum in the 7th gestational month, cryptorchidism affects more premature neonates (about 30%) than full-term neonates (about 3%). In about 80% of affected neonates, the testes descend spontaneously during the first year; in the rest, they may descend later.

The prognosis for recovery is excellent because one or both testes usually descend spontaneously. If this doesn't occur, orchiopexy (fixation of a viable testis to the scrotum) can readily correct the disorder.

Causes

Undescended testes may occur for several reasons. While prematurity is a leading cause, other causes may include hormonal disorders, spina bifida, retractile testes (a reflex that causes a testicle to move back and forth from the scrotum to the groin), or testicular absence.

Signs and Symptoms

There are usually no symptoms other than inability to find the testicle within the scrotum (may be described as an empty scrotum). Adult males with an undescended testicle may complain of infertility.

Diagnostic tests

The laboratory tests used to determine sex in questionable situations are a buccal smear, which is used to identify gender (by showing a male sex chromatin pattern), and serum gonadotropin analysis, which confirms existing testes by evaluating hormone levels in circulation.

Treatment

If the testes don't descend spontaneously by age 1, surgical correction (orchiopexy) may be needed to secure the testes to the scrotum. Commonly performed before the patient reaches age 4, orchiopexy prevents sterility, injury related to abnormal testicular position, and harmful psychological effects.

In some patients, human chorionic gonadotropin given intramuscularly may stimulate descent. This therapy is ineffective if the testes lie in the abdomen or if the patient also has an inguinal hernia.