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A spermatocele is a cyst that develops in the epididymis — the small, coiled tube situated in the upper testicle that collects and transports sperm. Generally painless and noncancerous (benign), a spermatocele usually is filled with milky or clear fluid that may contain dead sperm.

Spermatoceles are usually less than 2 to 3 centimeters in diameter, although some may be larger. Most of the volume of the cyst is fluid.

A common condition, a spermatocele doesn't impair fertility, nor does it require treatment unless is grows large enough to cause discomfort. In that case, your doctor may suggest surgery to treat the spermatocele.

A spermatocele usually causes no signs or symptoms and may remain stable in size. If it becomes large enough, however, it may cause the following sensations in the affected testicle:

• Discomfort
• Pain
• A feeling of heaviness

No one knows what causes a spermatocele. Many experts believe it results from a blockage in one of the tubes that drain sperm from the testicle into the epididymis. Trauma and inflammation also may cause spermatoceles.

The risk of developing a spermatocele increases with age. Spermatoceles are most often found in men between the ages of 40 to 60.

Because a spermatocele usually produces no symptoms, you may discover it only during a testicular self-exam, or your doctor may find it during a routine physical exam. It's a good idea to have your doctor evaluate any scrotal mass to rule out a serious condition, such as testicular cancer. Especially if you experience pain or swelling in your scrotum, contact your doctor. A number of conditions can cause testicular pain, and some of the conditions require immediate treatment.

Screening and diagnosis entail a physical exam. Although a spermatocele usually isn't painful, you may feel discomfort when your doctor examines (palpates) the mass.

You may also undergo the following diagnostic tests:

• Transillumination. Your doctor may shine a light through your scrotum. With a spermatocele, the light will indicate that the mass is fluid-filled rather than solid.
• Ultrasound. If transillumination indicates a fluid-filled mass, your doctor may order an ultrasound to confirm the diagnosis. If transillumination doesn't clearly indicate a cyst, an ultrasound can help determine what else it might be. This test, which uses high-frequency sound waves to create images of structures, may be used to rule out a testicular tumor or other cause of scrotal swelling.

Other tests usually aren't necessary. However, if the ultrasound is inconclusive, your doctor may request magnetic resonance imaging (MRI), which uses a magnetic field and radio waves to create cross-sectional images of your body.

A spermatocele is unlikely to cause complications. Sperm normally travel through the tubes of the epididymis. A blocked tube causes the sperm to die, which is why a spermatocele may be filled with dead sperm. However, even if one of the tubes that drains sperm is blocked, others remain open, allowing sperm through. So spermatocele doesn't affect the overall transport of sperm or impair fertility. However, surgical removal may damage the epididymis or the vas deferens, a tube that transports sperm from the epididymis. Damage to either can impair fertility.

Most spermatoceles require no treatment. If yours causes discomfort, your doctor may recommend that you take over-the-counter pain medications, such as acetaminophen (Tylenol, others) or ibuprofen (Motrin, Advil, others).

Surgical treatments
Repairing a spermatocele requires surgery to remove the cyst. A procedure called a spermatocelectomy generally is performed on an outpatient basis, using local or general anesthetic. The surgeon makes an incision in the scrotum and separates the spermatocele from the epididymis. After surgery, you may need to wear a gauze-filled athletic supporter to apply pressure to and protect the site of the incision. Other post-surgical instructions may include:

• Applying ice packs for two or three days to keep down swelling.
• Taking oral pain medications.
• Returning to your doctor for a follow-up exam two to three weeks after surgery.

A less-used treatment is sclerotherapy, which involves puncturing the spermatocele with a needle, withdrawing the fluid and injecting an irritating agent into the sac. The irritating agent causes the sac to scar, which eliminates the space the fluid occupied and may lower the risk of recurrence. However, the incidence of recurrence is high, as is the risk of damage to the epididymis. Sclerotherapy usually is used only for men who are beyond their reproductive years and who have conditions, such as blood clotting problems, that increase the risks of spermatocelectomy.

Although there's no way to prevent a spermatocele, it's important for you to conduct scrotal self-exams at least monthly to detect changes in your scrotum, such as masses. Your doctor can instruct you in how to conduct a self-exam.

A simple procedure called testicular self-examination (TSE) can improve your chances of finding a mass. Beginning in your midteenage years and continuing throughout your life, examine your testicles at least once a month.

How to examine your testicles
A good time to examine your testicles is after a warm bath or shower. The heat from the water relaxes your scrotum, making it easier for you to detect anything unusual. Then follow these steps:

• Stand in front of a mirror. Look for any swelling on the skin of the scrotum.
• Examine each testicle with both hands. Place the index and middle fingers under the testicle while placing your thumbs on the top.
• Gently roll the testicle between the thumbs and the fingers. Remember that the testicles are usually smooth, oval shaped and somewhat firm. It's normal for one testicle to be slightly larger than the other is. Also, the cord leading upward from the top of the testicle (epididymis) is a normal part of the scrotum.

By regularly performing this exam, you will become more familiar with your testicles and aware of any changes that might be of concern. If you find a lump, call your doctor as soon as possible.

Regular self-examination is an important health habit. But it can't substitute for a doctor's examination. Your doctor should check your testicles whenever you have a physical exam. If you have an undescended testicle — less than two testicles in your scrotum — be sure to tell your doctor, who may refer you to a urologist for treatment or a more specialized exam.

You may be able to relieve discomfort by taking over-the-counter pain relievers such as acetaminophen (Tylenol, others) or ibuprofen (Motrin, Advil, others).