The sac of skin that contains the testicles is called the scrotum. A scrotal mass is an abnormal bulge or lump inside the scrotum.

A scrotal mass can be a swollen testicle or it can contain fluid or other tissue. It’s possible that the mass could be cancerous, but there are also a number of noncancerous causes of a mass in the scrotum.

The symptoms you experience will vary depending on the cause of your scrotal mass. In some cases, there aren’t any symptoms other than a mass that you can feel with your fingers.

Other symptoms might include:

  • pain that spreads to your groin, abdomen, or back
  • sudden pain or a dull ache in your scrotum
  • a feeling of heaviness in your scrotum
  • redness of the scrotum
  • a swollen scrotum
  • hard or swollen testicles
  • a swollen, tender epididymis, which is the tube located behind your testicles that stores and transports sperm

If your scrotal mass is the result of an infection, you might have a fever and feel you need to urinate more often. There might also be blood or pus in your urine.

Many conditions can cause scrotal masses.

Orchitis

Orchitis is inflammation of the testicle. Although orchitis can occur in both testicles simultaneously, it typically only affects one testicle.

Orchitis can be caused by a bacterial or viral infection and is commonly associated with the mumps.

Epididymitis

Epididymitis is inflammation of the epididymis.

Most cases of epididymitis are caused by a bacterial infection. In people under 35 years old, epididymitis is most often caused by a sexually transmitted infection (STI), such as chlamydia. Older people are often diagnosed with nonsexually transmitted epididymitis.

There’s also a rare form of the condition known as chemical epididymitis. It can be attributed to urine flowing into the epididymis.

Hydrocele

A hydrocele occurs when one of the naturally occurring sacs that surrounds each testicle fills with fluid.

These sacs normally contain only a small amount of fluid. If the fluid collects, swelling can take place.

Hematocele

A hematocele is a type of blood clot that occurs when one of the sacs surrounding each testicle fills with blood. It’s usually associated with trauma or a prior surgery.

Spermatocele

A spermatocele occurs when a benign and typically painless cyst develops near one of the testicles. Although spermatoceles are usually harmless, they can get quite large and become bothersome due to their bulk.

Other names for this condition include spermatic cyst and epididymal cyst.

Varicocele

A varicocele is an enlarged vein in your scrotum. Varicoceles mostly affect the left testicle.

They’re usually not symptomatic, but they can cause fullness, pain, aching, or even infertility in some cases.

Inguinal hernia

An inguinal hernia occurs when fatty or intestinal tissue bulges through a weak section of your abdominal wall. It’s also known as a groin hernia.

Testicular torsion

Testicular torsion occurs when the spermatic cord, which connects your penis to your testicles, gets twisted.

Most people with testicular torsion are teens. This condition is painful, rare, and appears to have a genetic component.

Seek immediate medical attention if you experience severe testicle pain. Testicular torsion is a surgical emergency. People who have it need to be brought to the emergency room as soon as possible for repair. If not, then they risk testicular loss.

Testicular cancer

Testicular cancer starts out as abnormal cells in the testicles and can be a potential cause of scrotal masses.

Some causes of scrotal masses don’t require immediate attention. However, it’s generally a good idea to talk with your doctor about any masses in your scrotum.

Other causes of scrotal masses can result in permanent damage to your testicles.

Your doctor can help properly diagnose and treat any masses you find.

Tests that they may perform in order to diagnose your condition include:

If your scrotal mass is the result of a bacterial infection, antibiotics will be a part of your treatment. If you have a viral infection, the best course of treatment is rest and pain medication.

In other scenarios, your doctor may simply leave the mass alone, depending on its size.

If the mass is noncancerous and doesn’t cause you severe pain or discomfort, you may not need treatment.

If your mass causes you discomfort, it might be removed. It can be surgically removed or your mass might be drained of fluid as is done for a hydrocele. Testicular torsion is considered a medical emergency and is almost always treated with surgery.

For testicular cancer

If the masses in your scrotum are caused by cancer, speak with a cancer treatment specialist to evaluate whether or not you’re a good candidate for treatment.

Important factors in determining if cancer treatment is right for you are your age, your overall health, and whether the cancer has spread outside of your testicles.

Treatments for cancer include:

  • radical inguinal orchiectomy, which involves the surgical removal of your affected testicle and your spermatic cord
  • radiation therapy to destroy cancer cells that can be left behind after surgery
  • chemotherapy

You can help prevent scrotal masses caused by STIs by using condoms or other barrier methods during sex. While these methods aren’t 100 percent effective against all STIs, they can help reduce your risk.

Wearing a cup while playing sports will protect your testicles from injury.

Checking your scrotum and testicles for lumps each month can also help you and your doctor detect any problems as early as possible.