Testicles form within the lower abdomen and then move into the scrotum at around 28 weeks of pregnancy. The most common birth abnormality is a testicle that does not reach the normal location before birth. Two-thirds of these will move into the scrotum in the first few months of life. A testicle that does not reach the normal scrotum location by 6 months of age will not move afterwards and so most often surgery is recommended.
An undescended testicle usually is felt outside the abdomen. Nearly all that can be felt are located next to the base of the penis in the upper scrotum and only need to be moved further down. There is usually a hernia-like sac that is also removed during the operation. Less commonly, a testicle is located within the abdomen and cannot be felt on routine exam.
Traditionally surgery for undescended testicles in the groin have been performed making 2 incisions, one in the groin to remove the hernia-like sac and another in the scrotum to place the testicle. However the same operation can be done with the same high success rates with only 1 incision in the skin folds of the scrotum (ref), which leaves a barely visible scar. The surgeons at PARC Urology use this single scrotal incision operation for nearly all patients. Surgery for a testicle that is in the abdomen and cannot be felt in the groin is usually done using laparoscopy (tiny instruments through small incisions in the abdomen).
There are 3 reasons given for this surgery. One is for the health of the testicle to preserve fertility. However, the majority of boys with an undescended testicle have it on only 1 side with the other testicle in the scrotum. The best available information regarding this situation is that these patients have similar fertility as those born with both testicles descended. A second reason is concern for cancer as a teenager or adult; fortunately the risk for cancer developing after surgery is very low – less than 1%. (ref) The third reason is to make the scrotum appear more normal by having a testicle on each side.
Here is a child with an undescended left testicle. Notice how the scrotum looks lopsided without a testicle in it. The undescended testicle most often is found in the upper scrotum next to the base of the penis.
Appearance of the scrotum after a single incision was used for surgery (on the patient’s left side). There is no scar in the groin and the incision in the scrotum is barely visible.