Cryptorchidism, or undescended testes, is the most common genital abnormality in boys. Research shows one-in-100 male infants are affected, and approximately 30 percent of baby boys born prematurely.
“Testicles are mobile structures, and it is normal for a testis to move up and down over the course of a day,” says Boston Children’s Hospital urologist, Michael Kurtz, MD, MPH. “Moreover, lymph nodes can appear similar to the testis on imaging.”
Kurtz says the main challenge pediatricians face is distinguishing a retractile testis (a testicle that pulled upward by muscle) from an undescended testis. “And only the latter requires surgery,” he adds.
Notes sat down with Kurtz and discussed when and why it’s important to treat undescended testes early, common misconceptions, and when to refer to a pediatric urologist.
What information do you feel pediatricians need to know about cryptorchidism?
Kurtz: The most important piece of information is to refer patients with undescended testes early, around four-to-five months of age. Surgery is typically performed between six and 12 months of age. Research from our department has shown that the average patient age at orchidopexy in the U.S. is 3.9 years, and ideally this would be under age one.
Secondly, the physical exam can be challenging. If a retractile testis is suspected, once the testis is gently positioned in the scrotum and held there for 30 seconds the muscle attached to the testis will become fatigued. If the testis then sits in the scrotum on no tension, the diagnosis of retractile testis is made. If the testis continues to be pulled upward after the muscle is fatigued, then this represents an undescended testis. This requires surgery.
Lastly, it is surprisingly easy to mistake components of a hernia sac for a testicle. A newborn testis is only approximately 0.5cc’s in volume, with maximum length around 9mm, or 3/8ths of an inch. Small intrascrotal folds can feel similar.
When should a patient be referred to a pediatric urologist?
Kurtz: If the undescended testis is associated with hypospadias or any concern regarding the remainder of the exam of the genitalia, a pediatric urologist should be seen soon after birth. Otherwise, there is no urgency. Testicles do descend in the first three months of life, especially in babies born prior to full term. That said, descent of the testis beyond the first three months is rare. We aim to correct the position of an undescended testis via surgery between six and twelve months of age.
Can you describe the surgical procedure?
Kurtz: All cases are performed as day surgery – patients and their families get to go home from the recovery unit – and all are performed under a general anesthetic with the baby completely asleep for the procedure. Local numbing medication is used at the end of the case to help with postoperative pain. This type of procedure hinges on the location of the testis.
For palpable inguinal testes, we make a small inguinal incision to repair the associated hernia and to create enough length to allow the testis to reach the scrotum. We then make a small incision in a scrotal fold to create a pocket that holds the testis. There are special anatomic circumstances in which a single incision may be used.
For the nonpalpable testes, the approach is somewhat more complex. In the operating room, we begin by performing a laparoscopy, which is an examination inside the abdomen with a small camera placed in the umbilicus. Some patients simply will not have a testis found, which is thought to be due to an error during development or twisting of the testis inside the abdomen.
If a testis is found in the abdomen there are three possibilities. The first, which is optimal, is that the testis can be brought to the scrotum leaving the blood supply and vas deferens intact. This is often not possible, as the vessels are quite short when the testis is in the abdomen. The second and third options are to divide the blood vessels a move the testicle to the scrotum; in one procedure we wait approximately 6 months between steps and use a second anesthetic which may allow for more blood vessel growth, and in the other we move the testiscle right away, which has the advantage of occurring under a single anesthetic. It is truly not known in the field which approach is better, and we are currently conducting a trial at Boston Children’s Hospital to determine the best option for babies and toddlers.
Do undescended testes impact puberty?
Kurtz: Typically not. After orchidopexy, most boys will go on to have normal pubertal growth.
Is there increased infertility in boys with undescended testis?
Kurtz: This is complex. Boys with one-sided undescended testes have fertility rates that nearly match the general population of men. Boys with bilateral undescended testes have a higher risk of subfertility. Surgical repositioning of the abdominal testes into the scrotum, in addition to reducing the risk of occult testis cancer, dramatically increases the chance of fertility.
Are there any common misconceptions about cryptorchidism?
Kurtz: The main misconception surrounds hormonal therapy based on older literature. In the past, injections of human chorionic gonadotropin (hCG) were used to encourage movement of the testis to the scrotum and hopefully avoid surgery. It was effective in a maximum of 20 percent of patients, required several injections, and had frequent side effects. We no longer use this modality of therapy.
Are boys with undescended testes prone to testicular cancer? If so, what long-term course of action should be taken?
Kurtz: Testis cancer is in itself very rare. Approximately 8,720 men and boys in the U.S. will be diagnosed with testis cancer in 2016, and there is a four-in-1,000 chance for a boy developing testis cancer during his lifetime. Given the overall low probability, I try to reassure families regarding these facts. That said, there is an increased relative risk of boys with undescended testes, approximately two-to-three fold higher than the general population. In boys undergoing orchidpexy after age 13 or pubertal onset, the risk appears to be substantially higher. We recommend once old enough that all boys perform testicular self-exam after orchidoepxy.
Michael P. Kurtz, MD, MPH trained in urology at Massachusetts General Hospital and pediatric urology at Boston Children’s Hospital. His research and clinical interests include robotic reconstruction, kidney stone treatment and prevention, and fetal care for babies with congenital abnormalities.