What is an undescended testicle?

The testicles are formed inside the abdomen, and they gradually migrate down. In the last few weeks before the birth of the child, they pass through the abdominal wall muscles and groin to their normal position in the scrotum. Any testis that is not located in the scrotum is undescended. This condition is fairly common, occurring in 3 percent to 5 percent of full-term boys at birth, with a much higher incidence in premature infants. However, the majority of undescended testicles will descend to a normal position within the first three to six months of life. Approximately 0.8 percent to 1 percent of full-term boys will continue to have an undescended testis at a year of age, requiring treatment. There may be several reasons why a testicle is not in the scrotum:

• The testicle may never have formed to begin with.

• The testicle may have shrunken before birth because of a twist or blockage of its blood vessels.

• The testicle may have not descended properly but remains within the abdominal cavity.

In the above conditions, the testicle will not be found on a physical examination, referred to as an impalpable testicle. The testicle may have descended incompletely and may be in the groin or between the abdominal muscles (inguinal canal), just above the scrotum.

Diagnosis

Undescended testicles are usually diagnosed by physical examination. The initial evaluation is done during the newborn period, followed by periodic examination during well-child visits. Treatment is recommended if the testicle is located in the groin and cannot be brought down into the scrotum (undescended testicle) or if it is not found either in the scrotum or in the groin (impalapable testicle) by the age of six months to a year.

While the impalpable testis may occasionally be identified on radiological tests such as an ultrasound, CT scan or MRI, none of these tests are conclusive enough to be recommended routinely in these situations.

The testicles need a slightly cooler environment than the normal body temperature for optimal functioning and especially for sperm production. Thus, if both testicles are left undescended, there may be a risk of infertility. Locations outside of the scrotum may expose the testicle to a higher risk of injury. Undescended testicles are also associated with hernias. In addition, undescended testicles are at a higher risk of developing testicular cancer in adulthood. Testicular cancer, if identified and treated early, has a high cure rate. Early identification is only possible if the testicle is located in the scrotum; therefore, this is an important reason to treat undescended testicles.

Treatment

Recent evidence suggests that most spontaneous descent occurs by six months of age. Damage to the germ cells, which give rise to sperm later in life, has been noted to occur as early as 12 to 18 months. For these reasons, we recommend treatment around the age of 9 to 12 months. Two main avenues of treatment are available — hormone injections and surgery. Human chorionic gonadotrophin (HCG) has been used, but reported success rates are low and unpredictable. Surgical treatment, or orchiopexy, is usually done as an outpatient through a small incision in the groin. Any hernias associated can be corrected at the same time, and the testis is placed in a pouch created under the scrotal skin. 

With an impalpable testis, a laparoscopic examination is performed through a keyhole incision in the umbilicus to identify the presence and location of the testicle. If only a remnant is identified, it can be removed. On the other hand, if the testicle is a good size, it can be brought down into the scrotum after laparoscopic dissection of the blood vessels to obtain adequate length. Occasionally, this may require a two-stage operation if not enough length is initially obtained. Surgical treatment is usually an outpatient procedure (laparoscopic or open). All incisions are closed with absorbable sutures. The child may require prescription pain medicine for approximately 48 hours. Older children will need a week off from school and a total of three to four weeks away from playground and straddling activities.

If treated early, there is a good chance that the affected testicle will develop normally. In some cases, the testicle is abnormal to begin with and its growth may be affected. However, if the other testicle is normal fertility may not be an issue. The undescended testicle needs to monitored long-term, and these children should be taught testicular self examination to be performed monthly. If the testicle is absent or was removed due to poor development, a testicular prosthesis is an option. These are made of silicone and are available in different sizes. In order to avoid multiple operations to keep upsizing the prosthesis, we recommend waiting until puberty to determine the size required to match the remaining testis. In some teenagers affected psychologically by the loss of a testis, a testicular prosthesis may help improve their self-image.