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Scrotal masses are areas of fluid or solid material in, on or around the testicles. Although they may indicate a less serious or harmless condition, scrotal masses also may be a sign of something as serious as cancer.

The testicles play two important roles: They produce sperm cells used in reproduction, and they secrete hormones such as testosterone that play a key role in male body development. The location of the testicles in the scrotum, a loose bag of skin underneath the penis, keeps them at a temperature lower than that within the abdominal cavity. The lower temperature is needed for adequate sperm production.

The relatively exposed location of the testicles and scrotum makes them prone to injuries, but it also makes them easy to examine for the presence of scrotal masses.

You can develop scrotal masses at any age. Have your doctor check out any unusual lumps or swelling in, on or around your testicles. Treatment of scrotal masses depends on the cause.

The testicles (testes) are located inside the scrotum, a loose bag of skin below the penis. They produce male hormones and sperm. Signs and symptoms of scrotal masses include:

• A lump or swelling in the scrotum
• Local pain or tenderness

Scrotal masses have various causes, including cysts, infection, inflammation, inguinal hernia and tumors. The tumors may be noncancerous (benign) or cancerous (malignant). Tumors growing within the testicles most often are malignant, whereas those located elsewhere within the scrotum are usually benign. Because of the possible seriousness of a scrotal mass, it's important to have a doctor check out any swelling or lumps. Specific causes of scrotal masses include:

• Epididymitis. This infection in the tubular coil (epididymis) that collects sperm from the testes produces pain in the top and rear of the scrotum. The pain is generally severe and develops gradually over several hours or days. Fever and swelling also are common.
• Spermatic cyst (spermatocele). This common type of painless, benign cyst develops adjacent to the epididymis near the top of the testicle.
• Hydrocele. This soft, usually painless swelling in the scrotum is a collection of watery fluid in the sheath that holds the testicle. Normally this sheath contains just enough fluid to lubricate the testicle. When the body produces too much fluid or can't absorb enough fluid, the excess liquid creates a hydrocele. Hydroceles are a common cause of scrotal swelling and may occur on one or both sides. A hydrocele may occur at any age, but occurs most often in older men.
• Varicocele. Enlarged (varicose) veins cause this painless, benign source of scrotal swelling, more commonly on the left side. Blood backs up in the veins leading from the testicles because of a problem with valves inside the veins. The swelling is painless, and the area feels like a bag of worms. This sensation may disappear when you lie down. The varicocele itself isn't serious, but it may contribute to infertility.
• Orchitis. This inflammation of the testicle is often due to a bacterial infection or the mumps virus. It involves pain and swelling in the scrotum along with a feeling of added weight in the scrotum. Orchitis may also occur when there's an infection of the prostate or the epididymis. Many less common diseases may have orchitis among their manifestations. Orchitis can permanently damage one or both testicles, resulting in diminished size of the testicle, inadequate hormone production and infertility.
• Inguinal hernia. An inguinal (ING-gwih-nul) hernia develops when abdominal contents, usually the small bowel, protrude through a weak point of the abdominal wall in the groin area, where the blood vessels and ducts from the testicles enter the abdominal cavity. The result is a bulge in the groin area that may extend into the scrotum and be painful or uncomfortable.
• Cancer of the testicle. This condition is serious and identified by a lump or swelling within a testicle, sometimes accompanied by a heavy feeling in a testicle. If detected and diagnosed early, this type of cancer often is treatable.

See your doctor if you detect any pain, swelling or lumps in your testicles or groin area, especially if these signs and symptoms last longer than one to two weeks. Make an appointment with your doctor even if a lump in your testicle isn't painful. Only a small percentage of testicular cancers are painful initially.

Most men discover scrotal masses themselves, either unintentionally or while doing a testicular self-examination to check for lumps.

If you alert your doctor to a scrotal mass, or he or she discovers a lump during a routine office visit, a physical exam and lab tests can confirm an infection or another cause. You may also undergo an ultrasound examination. This painless test passes sound waves through your scrotum to make an image of the contents of your scrotum.

Most scrotal masses require minimally invasive treatment or no treatment at all, but some require more serious procedures.

• Epididymitis. This usually acute condition can be treated with antibiotics.
• Spermatocele. Most spermatoceles are small, cause no symptoms and require no treatment. However, sometimes they can grow large enough to cause signs and symptoms such as pressure, pain or swelling in the scrotum and require surgical removal. Draining the fluid by puncturing the spermatocele through your skin may provide temporary relief. But the fluid invariably accumulates again within a few weeks.
• Hydrocele. Usually, you don't need treatment for a hydrocele unless the scrotum is so swollen that it's uncomfortable.
• Varicocele. If you have a varicocele that's contributing to infertility, surgically tying off the varicocele (ligation) improves your chances of becoming fertile again.
• Orchitis. Doctors use antibiotics to treat orchitis associated with bacterial infections. Treatment for orchitis associated with viral infections such as mumps is only by conservative means such as rest and pain-relieving medications.
• Inguinal hernia. Your doctor may recommend surgery if your hernia is painful or bothersome. Hernias can recur after surgery, but this happens less than 10 percent of the time.
• Cancer of the testicle. Stage I testicular cancer, in which cancer is found only in the testicle, and stage II testicular cancer, in which cancer has spread to the lymph nodes in the abdomen, are successfully treated in most cases. Stage III testicular cancer, in which cancer has spread beyond the lymph nodes to other regions of the body, such as the lungs or liver, is successfully treated in about 70 percent of cases.

Generally, doctors use the following treatments for testicular cancer:

• Radical inguinal orchiectomy. This surgical procedure involves removal of one or both testicles through an incision in the groin. Lymph nodes in the abdomen also may be removed (lymph node dissection). If only one testicle is cancerous and removed, there is a small chance that the other testicle will become cancerous at some time. As a result, your doctor will likely recommend regular follow-up exams with a urologist.
• External beam radiation therapy. This treatment uses high-dose X-rays or other high-energy radiation to kill cancer cells.
• Chemotherapy. Chemotherapy is used to kill cancer cells outside the testicle. This drug therapy is usually given by intravenous (IV) infusions, typically in the hospital, several days each month. In some cases, chemotherapy may also be given by intramuscular injection or in pill form. Chemotherapy has made the biggest difference in reducing death from testicular cancer.
• Bone marrow transplant. In this procedure, some of your bone marrow is removed, treated with drugs to kill any cancer cells and then frozen. You then undergo chemotherapy, with or without radiation, to destroy the remaining cancer cells in your body. This chemotherapy also destroys your remaining bone marrow. The frozen marrow is then thawed and injected back into you through a needle in a vein. This relatively new treatment for testicular cancer has had some promising initial results. Yet it's not routinely recommended by doctors because traditional chemotherapy treatments are typically very successful.

Surgery may be in combination with radiation therapy or chemotherapy or both. Your treatment depends on the type and stage of your cancer. Your age and overall health also are factors in choosing treatment options for testicular cancer.

A simple procedure called testicular self-examination can improve your chances of finding a tumor. Whatever your age, starting in your midteenage years, examine your testicles regularly.

It's a good idea to examine your testicles once a month, after a warm bath or shower. The heat from the water relaxes your scrotum, making it easier for you to check for anything unusual. Your doctor should also examine your testicles when you have a physical exam.

To do the examination, 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 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. 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. Testicular cancer is highly treatable, especially when found promptly.

Regular self-examination is an important health habit. But it can't substitute for a doctor's examination. Ask your doctor to check your testicles whenever you have a physical exam.

If you have an undescended testicle, tell your doctor, who may refer you to a urologist for treatment or a more specialized exam. Having an undescended testicle increases your risk of testicular cancer. Surgical correction of an undescended testicle — moving it from your abdomen down into your scrotum — can reduce your risk.