It is possible to develop a fluid filled sac or cyst on the epididymis, which is the small tube that stores and transports semen from the testicles. Doctors refer to these sacs or cysts as spermatoceles.

These benign growths often have unknown causes and do not cause any symptoms.

If a spermatocele does not cause symptoms or grow large enough for the person to discover it during a self-exam, they may never seek a diagnosis.

This article explains what spermatoceles are, the possible symptoms, and how doctors diagnose and treat them.

A black and white image of the testicles seen under a microscope.Share on Pinterest
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A spermatocele is a small, fluid filled sac that develops on the epididymis. The epididymis is a small, coil-like tube that transports sperm from the testicles to the penis.

Spermatoceles are typically painless and benign, meaning that they are not cancerous. A white fluid usually fills them, and they may also contain sperm.

Spermatoceles can vary in size. Although these growths are not harmful, a person may wish to seek treatment if a spermatocele grows too large or causes pain.

Spermatoceles are fairly common, and estimates suggest that they may occur in nearly 1 in 3 people with testicles. However, few people with a spermatocele seek a medical examination. The reasons for this include a lack of awareness of the growths and the fact that they are benign.

Often, people do not experience any symptoms when they have a spermatocele. However, people can check for the following when examining their testicles.

Sensations

For most people, spermatoceles are smooth, hard, painless lumps that do not cause any noticeable symptoms. They may remain stable in size and asymptomatic.

In others, however, the cyst can grow in size. As the cyst grows, a person may notice issues such as:

  • a heavy feeling testicle
  • a feeling of fullness above or behind the testicle
  • discomfort or pain in the affected testicle

A person may also notice or feel the lump when examining their testicles. They may feel pressure at the base of the penis.

Appearance

Spermatoceles are clear, fluid filled sacs or cysts that sit above and behind the testicle. As they reside inside the skin of the scrotum, it is not possible to see them during a visual exam without the aid of specialized diagnostic equipment.

However, if a spermatocele has become particularly large, it may lead to swelling. A person may notice that the affected testicle appears larger than the other one.

The exact cause of spermatoceles remains unknown.

One theory is that they may result from a blockage of the epididymis.

However, they are benign masses. They also have no link to testicular cancer and do not interfere with fertility.

A person may feel the lump when performing a self-exam. According to an older study from 2009, people with testicles often do not seek a diagnosis or treatment right away, even when they discover a lump.

The authors note that the average size of the spermatoceles that doctors examine is similar to that of a testicle.

A person will usually need to see a urologist for a diagnosis. A urologist may test the cyst using a bright light, which will shine through a noncancerous cyst because, unlike a tumor, it is not a solid mass. They might also use ultrasound, a type of scan that uses sound waves that bounce off tissues to detect abnormalities.

Many people with spermatoceles will not need treatment. People who seek treatment often have larger or painful growths.

The treatment options can include:

  • spermatocelectomy, which is an outpatient surgical procedure that removes the cyst
  • oral pain relief and inflammation medications
  • aspiration, which is an uncommon procedure that punctures the cyst and draws out the fluid with a needle
  • sclerotherapy, in which a doctor injects an irritant into the cyst to cause scarring and reduce its chances of growing again

It can take about 1–2 weeks to recover from surgery. A doctor may recommend pain medication for 1–2 days following the procedure. During recovery, a person will likely need to wear a supportive strap. They will typically notice scrotal swelling.

A doctor will want to schedule a follow-up appointment within 3 weeks of the procedure.

A person should ask the doctor about their recommendations for post-procedure care.

A spermatocele is a fluid filled sac or cyst that develops on the tubing connecting the testicle to the rest of the reproductive system. It is noncancerous and filled with a white fluid.

Most cases are not painful and will not require treatment. People usually only seek treatment if they experience pain or the size of the growth makes it uncomfortable.

Treatment is generally minimally invasive, and a person can expect to make a full recovery within a few weeks.