Epididymal cyst

An epididymal cyst is a fluid-filled sac that forms in the epididymis. The epididymis is a long, coiled tube behind each testicle that stores and carries sperm.

The cyst usually feels like a smooth lump above or behind the testicle. It is benign, meaning it is not cancer. It is also separate from the testicle itself, although this may not be easy to tell by touch.

The term spermatocele is often used for the same type of lump. More precisely, a spermatocele contains fluid and sperm, while a simple epididymal cyst contains clear fluid. They usually cause similar symptoms and are managed in much the same way.

Most epididymal cysts are small, painless, and do not need treatment. A larger cyst may cause heaviness, swelling, or discomfort. Any new scrotal lump should still be assessed because several conditions can cause lumps in this area, and examination alone may not always identify the cause.

An epididymal cyst does not normally damage the testicle or turn into cancer.

You may notice an epididymal cyst while washing, dressing, having sex, or checking your scrotum. Some are found during an examination or scan for another reason.

Possible features include:

• A smooth, rounded lump above or behind a testicle
• Swelling on one side of the scrotum
• A feeling of heaviness or fullness
• A mild or dull ache, especially with activity
• Discomfort when sitting or wearing tight clothing

The lump may be very small or may gradually become larger. Growth is often slow. Some people have cysts on both sides or more than one cyst.

An uncomplicated cyst does not usually cause redness, fever, severe pain, or a suddenly swollen testicle. Those symptoms may point to another problem, such as infection or testicular torsion. Torsion means the testicle has twisted and lost part of its blood supply; it needs emergency treatment.

A lump within the testicle may feel firmer and less separate than an epididymal cyst. You cannot reliably identify every scrotal lump by touch, so arrange an assessment rather than assuming that a new lump is a cyst.

The exact cause is often unknown. A cyst may form when fluid collects in one of the small tubes within the epididymis. A spermatocele may develop when a tube carrying sperm becomes blocked.

In adults, epididymal cysts may occur without an injury, infection, or other clear trigger. They are not caused by poor hygiene, sexual activity, masturbation, or a sexually transmitted infection.

Scrotal injury, inflammation, or previous surgery may sometimes affect the epididymal tubes, but many people with a cyst have no such history.

Epididymal cysts can also occur in children and teenagers. Most do not have an identifiable cause. A scrotal lump in a child should be examined so that other causes can be considered.

A healthcare professional will ask when you noticed the lump, whether it has changed, and whether you have pain or other symptoms. They may also ask about previous scrotal injuries, infections, operations, or fertility concerns.

During an examination, they will gently feel the testicles, epididymides, and surrounding structures. An epididymal cyst often feels smooth and separate from the testicle.

A light may be shone through the swelling. Fluid-filled lumps often allow light to pass through, a process called transillumination. This can provide useful information but does not confirm every diagnosis.

A scrotal ultrasound may be arranged if the cause is uncertain or the lump appears to come from the testicle. Ultrasound uses sound waves rather than radiation. It can show whether a lump is fluid-filled or solid and whether it sits inside or outside the testicle. It can also help identify other causes of swelling.

Blood tests are not usually needed for a straightforward epididymal cyst. They may be considered when symptoms or scan findings suggest another condition.

A small cyst that is not causing problems usually needs no treatment. Monitoring means noticing significant changes rather than repeatedly pressing or measuring the lump. Routine follow-up may not be required after the diagnosis is clear, although this will reflect the examination and scan findings.

For mild discomfort, supportive underwear may reduce movement and heaviness. Simple pain relief may help when it is safe for you to use; follow the product instructions or ask a pharmacist if you are unsure.

Surgical removal may be considered when a cyst is large, painful, steadily troublesome, or interfering with everyday activities. The operation is often called an epididymal cyst excision or spermatocelectomy. It separates the cyst from the epididymis, usually through a cut in the scrotum.

This is commonly a planned procedure rather than urgent treatment. Recovery can involve bruising, swelling, and soreness for days or weeks. Supportive underwear and temporary limits on lifting, exercise, and sexual activity may be advised after surgery.

Possible surgical complications include bleeding, infection, persistent pain, fluid collection, and recurrence. Surgery can also injure the epididymis or the vas deferens, the tube that carries sperm. This may affect fertility, particularly if both sides are involved or the other testicle does not function normally. Fertility plans are therefore important when weighing up an operation.

Draining a cyst with a needle is not generally a lasting solution because the fluid often returns. Injecting a substance after drainage to scar the cyst closed, called sclerotherapy, is used selectively and may also damage nearby sperm-carrying structures.

Most epididymal cysts cause no complications. They may remain stable for years or slowly increase in size.

A large cyst can cause ongoing heaviness, aching, or difficulty with exercise, sitting, or clothing. Significant discomfort is a reason for a routine review, especially if the diagnosis has not been confirmed.

An epididymal cyst does not usually affect testosterone production, erections, urination, or sexual desire. It also does not become testicular cancer. However, having a known cyst does not prevent an unrelated condition from developing, so a new or changing lump still deserves attention.

Problems are more likely to follow treatment than the cyst itself. These can include recurrence, a collection of blood called a haematoma, infection, chronic scrotal pain, or damage to sperm-carrying tubes.

There is no reliable way to prevent most epididymal cysts. They often develop without a known cause, and there is no evidence that changing sexual activity, diet, hygiene, or exercise will stop them forming.

Protecting the groin during contact sports can reduce the chance of injury, but it cannot guarantee that a cyst will not develop.

Becoming familiar with the usual shape and feel of your testicles may help you notice a new change. This does not prevent a cyst, and it is not a substitute for assessment of a new lump.

Many epididymal cysts stay small and cause little or no trouble. Once a typical cyst has been confirmed, it may not require regular scans or treatment. You can usually continue work, exercise, sex, and other activities as comfort allows.

Some cysts grow slowly over months or years. Size alone does not make a cyst dangerous, but increasing heaviness or discomfort may change whether treatment feels worthwhile. Arrange routine follow-up if the lump enlarges, becomes persistently painful, or begins to interfere with daily life.

Repeatedly squeezing the cyst will not make it disappear and may make the area sore. Supportive clothing can help during running, sport, or long periods of standing.

If future fertility matters to you, mention this before deciding on surgery. Observation may be preferable when symptoms are mild because an operation near the epididymis can affect sperm transport. If surgery is appropriate, the expected benefits and fertility risks can be discussed in advance.

Treatment can remove a troublesome cyst, but no procedure can promise that another cyst will never develop. Most people with an uncomplicated epididymal cyst continue their usual activities without major long-term effects.

Arrange a routine medical appointment for:

• Any new lump in or beside a testicle
• A known lump that is growing or changing
• Ongoing aching, heaviness, or swelling
• A lump that has not previously been examined
• Concerns about fertility or whether treatment is needed

Seek urgent medical advice if the scrotum becomes red, warm, or increasingly painful, particularly with fever, urinary symptoms, or discharge. These features may suggest infection or another condition rather than a simple cyst.

Go to an emergency department immediately for sudden, severe testicle or scrotal pain, especially with nausea, vomiting, a high-riding testicle, or rapid swelling. These may be signs of testicular torsion. Treatment is time-sensitive, and the pain should not be assumed to come from an existing cyst.

Is an epididymal cyst cancer?

No. An epididymal cyst is a benign fluid-filled lump and does not turn into testicular cancer. A new lump should still be examined because it may be difficult to tell whether it comes from the epididymis or the testicle.

Will an epididymal cyst go away by itself?

Some remain unchanged, and some may become smaller, particularly in children. Others persist or slowly enlarge. Treatment is usually based on discomfort and daily impact rather than waiting for every cyst to disappear.

Can an epididymal cyst affect fertility?

The cyst itself usually does not affect fertility. A very large cyst, cysts on both sides, or another epididymal problem may be relevant in some cases. Surgery can damage sperm-carrying tubes, so fertility plans should be discussed before an operation.

Can I exercise or have sex with an epididymal cyst?

Usually, yes. These activities do not normally make the cyst dangerous. If movement causes aching, supportive underwear or adjusting the activity may help. Persistent pain or sudden severe pain needs assessment.

What is the difference between an epididymal cyst and a hydrocele?

An epididymal cyst is a defined fluid-filled sac arising beside the testicle. A hydrocele is fluid collected around the testicle, often causing more general scrotal swelling. Examination and ultrasound can distinguish them.

When does an epididymal cyst need surgery?

Surgery may be considered when the cyst causes persistent pain, troublesome swelling, or interference with everyday life. A painless, confirmed cyst usually does not need removal. The possible benefit should be balanced against recurrence, pain, and fertility risks.