Cryptorchidism
What is Cryptorchidism (UDT, Undescended Testes)?
Cryptorchidism means hidden testicles (or testes). Testes are the male reproductive glands. They make sperm and testosterone. Most often, the testes move from inside the body to the scrotum before a baby boy is born. Cryptorchidism, or undescended testis (UDT), happens when something stops normal testes descent. So, one or both testes do not move all the way down to the scrotum.
What Are the Causes?
There are many causes. Sometimes, in babies born too early, there is not enough time for the testes to move from the abdomen to the scrotum. Sometimes, there are not enough of certain hormones (called androgens) before a baby is born. Other times, there is not enough pressure to move the testes down into the scrotum. UDT can also be a part of certain syndromes. At times, the cause is unknown.
How Common Is It?
UDT is common (see table). It is even more common in babies born too early. This happens because the testes finish their descent during the last 3 months of pregnancy. So, the testes of babies born too early often have not had time to travel down into the scrotum. As boys get older, the chances of having this are less. This happens because most undescended testes move down by themselves (without treatment) in the first year of life. In fact, in most cases, they move down within the first few months. If the testes have not moved down in the first year, treatment is needed.
|
Age |
Effect of Age on Rates of UDT |
|
Premature, under 2 pounds |
50 – 60% |
|
Premature, up to 5 pounds |
20 – 30% |
|
Term infants |
2 – 4% |
|
One year old |
0.5 – 1% |
|
Young adults |
under 1% |
UDT involves both testes (two-sided) in 10-30% of cases. When it involves only one testis (one-sided), it is more often the right one.
Where Can Undescended Testes (UDT) Be Found?
Testes that are not in the scrotum can be found in other places in the body (see picture below). They may be in the abdomen, the groin, or the side of the scrotum. In some parts of the body, the testes may be hard to feel during a physical exam.
Some testes go back and forth from the scrotum. This is often due to a very active muscle and poor attachment to the scrotum. This is common from ages 3 months to 7 years and is often called “retractile testes”. Often both testes are involved. After puberty these testes most often stay in the scrotum and are normal in size and function. A boy with retractile testes should be examined by a doctor on a regular basis to check that the testes eventually stay descended in the scrotum.
What Are the Risks?
A testis outside the scrotum does not develop in a normal way. When outside the scrotum, the body temperature is higher and the testes cannot move as easily. This disrupts the function, structure, and safety of the testes.
Infertility is a risk with two-side UDT and with one-side UDT if not treated. Testes in the groin and above are more likely to cause infertility. These risks are lowered if the testes are brought down into the scrotum before the age of 1-2 years.
The UDT has about 10-40 times the risk of cancer of the testes. Still, the risk is only about 1 tumor per 2000 undescended testes. About 10% of men with cancer of the testes have a history of UDT. Testes found above the groin have a higher risk of cancer.
Testes in the groin that cannot move freely are more prone to injury.
How is UDT Treated?
Since androgens (male hormones) and the placental hormone called hCG (human chorionic gonadotropin) are needed for the testes to descend, we can help the testes to make androgens by giving hCG. This hormone works better if the testes are lower. It is given as a shot 2-3 times per week for up to 3 weeks. The most common hCG side effect is that the penis gets slightly bigger. A baby with two-sided UDT should be assessed for hCG therapy before 1 year of age. For one-sided UDT, hCG treatment should be done between 1 and 2 years of age, especially if the testis is in a lower position.
If a child over 6 months of age gets no treatment for UDT and the testes are in the groin area or closer to the scrotum, he is sometimes treated first with hCG. If the hormone treatment causes the testes to descend all the way into the scrotum, surgery is not needed. If it only causes the testes to descend part of the way, then surgery is still needed. But, the surgery could be done with more ease if the testes are lower.
UDT is often treated with surgery. Early surgery (often before age 2 years) is recommended to allow for normal development of the testes. It also helps doctors to detect and treat tumors, if needed. Early surgery has a greater chance of improving fertility. The long-term effects of surgery on reducing cancer risks are still not clear.
The information provided should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Any duplication or distribution of the information contained herein is strictly prohibited.
Last Updated: 03/14/2008
Copyright © 03/14/2008 University of Wisconsin Hospitals and Clinics Authority. All rights reserved. Produced by the Department of Nursing. UWH #5349
Print Health Fact For You