A retractile testicle is a testicle that may move back and forth between its proper position in the bag of skin hanging behind the penis (scrotum) and the groin. When the retractile testicle is residing in the groin, it may be easily guided by hand into the scrotum during a physical examination.

For most boys the problem of a retractile testicle goes away sometime before or during puberty. When this happens, the testicle permanently moves to its correct location down into the scrotum.

Sometimes, the retractile testicle is no longer movable and instead stays up into the groin. When this happens, the testicle is no longer considered a retractile testicle. This condition is called an ascending testicle.

Testicles form in the abdomen during fetal development. During the final months of development, the testicles gradually descend into the scrotum. If your son has a retractile testicle, the testicle originally descended as it should, but then it didn't remain in place.

Signs and symptoms of a retractile testicle include the following:

• The testicle may be moved by hand into the scrotum and won't immediately "retreat" to the groin.
• It may spontaneously "appear" in the scrotum and remain there for a time.
• It may spontaneously "disappear" again for a time.

The movement of the testicle almost always occurs without pain or discomfort. Therefore, a retractile testicle is only noticed when you no longer see or feel it in the scrotum.

The position of one testicle is usually independent of the position of the other one. For example, a boy may have one normal testicle and one retractile testicle.

Retractile testicle is different from undescended testicle (cryptorchidism). The undescended testicle is one that never entered the scrotum. If a doctor attempted to guide an undescended testicle, it wouldn't move or would move slightly, most likely with some discomfort or pain.

An overactive muscle causes a testicle to become a retractile testicle. The cremaster muscle is a thin pouch-like muscle in which a testicle rests. When the cremaster muscle contracts, it pulls the testicle up toward the body.

The primary purpose of the muscle is to control the temperature of the testicle. In order for a testicle to develop and function properly, it needs to be slightly cooler than normal body temperature. When the environment is warm, the cremaster muscle is relaxed; when the environment is cold, the muscle contracts and draws the testicle toward the warmth of the body.

During childhood, the cremaster muscle may be particularly overactive. If this reflex is strong enough, it can result in a retractile testicle, pulling the testicle out of the scrotum and up into the groin.

Causes of an ascending testicle
About one-third of retractile testicles become ascending testicles. This means a once-moveable testicle can no longer be easily guided into position in the scrotum. Instead of being capable of moving up and down (retractile), the testicle is stuck in the "up position" (ascending).

A normal testicle residing in the scrotum — one that was never retractile — also can become an ascending testicle, or move permanently into the "up position."

The ascending testicle occurs because some part of the anatomy is pulling up on the testicle. Contributing factors may be:

• Short spermatic cord. Each testicle is attached to the end of the spermatic cord, which extends down from the groin and into the scrotum. The cord houses blood vessels, nerves and the tube that carries semen from the testicle to the penis. If growth of the spermatic cord doesn't keep pace with other body growth, the "shortened," or "tight," cord may pull the testicle up.

• Problem with the normal path of a descending testicle. Before a testicle descends during fetal development, a tiny bag-like extension of the abdominal lining creates a path for the testicle to follow into the scrotum. Normally the thin upper portion of this bag closes off, and any remnants of the upper portion disintegrate. Sometimes this structure fails to close off and detach from the abdomen, resulting in an upward pull on the testicle.

  In other cases, the top portion will close off, but a remnant of the structure remains and limits the growth or elasticity of the spermatic cord. Consequently, the spermatic cord pulls upward on the testicle.

• Scar tissue from hernia surgery. Incomplete closure of the bag-like extension from the abdomen may result in a small gap in the abdominal lining through which a portion of the intestines can push itself into the groin. This condition is called an inguinal hernia. Scar tissue following surgery to repair the hernia may limit the growth or elasticity of the spermatic cord.
• Other injuries. Scar tissue from a testicular infection or a traumatic injury also may limit the growth or elasticity of the spermatic cord.

During regular well-baby checkups and annual childhood checkups, your son's doctor examines your son's testicles to determine if they're descended and appropriately developed. If you believe that your son has a retractile or ascending testicle — or have other concerns about the development of his testicles — see his doctor. He or she will advise you on how often to schedule assessments to monitor changes in the condition.

If your son experiences pain in the groin or testicles, see your son's doctor immediately.

If your son has a testicle not located in the scrotum, his doctor will determine its location in the groin. Once it's located, the doctor will attempt to guide it gently into its proper position in the scrotum.

Your son may be lying down, sitting or standing during this examination. If your son is a toddler, the doctor may have him sit with the soles of his feet touching and knees to the side. Older boys may be asked to squat. These positions often make it easier to find and manipulate the testicle.

If the testicle is a retractile testicle, it will move relatively easily and painlessly. The retractile testicle won't immediately move up again. Your son's doctor can then stimulate the reflex of the cremaster muscle by gently rubbing the upper inside of the thigh. This stimulation will usually cause the retractile testicle to move up again.

If the testicle in the groin moves only part way into the scrotum, if the movement causes pain or discomfort, or if the testicle immediately retreats to its original location, it's most likely not a retractile testicle. In such cases the testicle would be considered undescended, or ascending if the testicle had been in the scrotum at one time.

If your son's doctor has any particular concerns about the diagnosis, he or she may refer your son to a pediatric urologist.

In order for a testicle to mature properly, it needs to be in the scrotum. Complications associated with undescended testicles — testicles that have never entered the scrotum — are well documented. Less is known about complications related to ascending and retractile testicles.

However, a boy with a retractile testicle may be vulnerable to these complications:

• Testicular cancer. Testicular cancer usually begins in the cells in the testicle that produce immature sperm. What causes these cells to develop into cancer is unknown. Men who have had an undescended testicle have a greater risk of testicular cancer.
• Fertility problems. Low sperm counts, poor sperm quality and low fertility rates are more likely among men who have had an undescended testicle.
• Testicular torsion. Testicular torsion is the twisting of the spermatic cord. This painful condition cuts off blood to the testicle. If not treated promptly, it may result in the loss of the testicle. An undescended testicle increases the risk of testicular torsion.
• Trauma. A testicle located in the groin may be susceptible to trauma or injury from compression against the pubic bone.

A retractile testicle is likely to descend on its own before or during puberty. If your son has a retractile testicle, your son's doctor will monitor any changes in the testicle's position in annual evaluations to determine if it stays in the scrotum, remains retractile or has become an ascending testicle.

If the testicle has ascended — no longer moveable by hand — or if it's still retractile by age 14, your son's doctor will recommend treatments. The goal of treatment is to have the testicle permanently descend, thereby lessening the risk of complications. Treatments include:

• Surgery. A surgical procedure called orchiopexy is the most common treatment. Through one incision in the groin and another in the scrotum, the surgeon guides the testicle to its proper position and stitches it into place. Annual follow-up exams are usually recommended.
• Hormone therapy. Because descent of the testicle is partially regulated by hormones, descent can sometimes be induced with hormone therapy using human chorionic gonadotropin (HCG). HCG is administered by injection, generally twice weekly for four weeks.

It is important to understand that even with successful treatment of an ascending or retractile testicle, the increased risk of cancer remains. But, if a testicle is permanently in the scrotum rather than in the groin, it's more easily monitored. Therefore, abnormal cancerous growths would be detected and treated sooner.

Adolescent boys and men who have had treatments to correct an ascending or retractile testicle should regularly monitor the position of the testicle to ensure it doesn't ascend at a later time.

You can help your son by being aware of the development of his body and talking to him about it.

• Check the position of the testicles regularly during diaper changing or at bath time. Keep a record of changes.
• Give your son the vocabulary to talk about the scrotum and testicles. Explain that there are usually two testicles in the scrotum.
• When he's about to reach puberty and you're talking about what physical changes to expect, explain how he can check the testicles himself.

If your son has a retractile testicle, he may be sensitive about his appearance. He may have anxieties about looking different from friends or classmates, especially if he has to undress in front of others in gym class. The following strategies may help him cope:

• Explain in simple terms what a retractile testicle is.
• Remind him that there's nothing wrong with him.
• Explain that the position of the testicle is something you, your son and his pediatrician will pay attention to and fix if necessary.
• Help him practice a response if he's teased or asked about the condition.
• Buy him loosefitting boxer shorts and swim trunks that may make the condition less noticeable when changing clothes and playing sports at school.
• Be aware of signs of anxieties, such as not participating in sports that he would normally enjoy.