What Is an Epididymal Cyst, and Does It Need Treatment?

An epididymal cyst is a smooth, fluid-filled lump that grows from the epididymis, the coiled tube that sits behind and above each testicle and carries sperm. It is benign (not cancer), it is common, and most cysts are small and painless and need no treatment. A doctor usually confirms it by examining the scrotum and, if needed, with an ultrasound scan.

Doctors may also call it a spermatocele or spermatic cyst; Cleveland Clinic treats these as the same condition. MedlinePlus describes a spermatocele as a cyst-like lump containing fluid and dead sperm cells. Cleveland Clinic says these cysts are found in nearly 1 in 3 adult males and most often appear in people in their 40s and 50s, although some are too small to feel and are only seen on a scan.

Sudden testicle pain can be testicular torsion, where the testicle twists and its blood supply is cut off. The NHS says the testicle can be lost without quick treatment, and MedlinePlus notes that most testicles can be saved if surgery happens within 4 hours. Torsion is most common between the ages of 10 and 20, but it can happen at other ages.

The NHS advises going to an emergency department or calling emergency services straight away for:

• Sudden, severe pain in a testicle.
• Testicle pain with feeling sick, being sick or tummy pain.
• Testicle pain that lasts more than an hour or continues when you are resting.
• Do not drive yourself; ask someone to take you or call for an ambulance. A known cyst does not explain new severe pain.

MedlinePlus advises having any scrotal lump examined as soon as possible, because a painless lump can occasionally be testicular cancer and a lump on the testicle itself may be its first sign. You cannot tell the cause by feel alone. The NHS says not to try to self-diagnose a lump and to see a doctor.

Ask for a prompt appointment if you notice a new lump or swelling, a change in the shape or feel of a testicle, one testicle getting bigger than the other, or aching that does not go away. Also get in touch if a cyst you already know about becomes painful, grows quickly, or the scrotum becomes red, warm or tender, or you develop a fever.

Cleveland Clinic describes a spermatocele as a smooth lump above or behind the testicle, separate from it. Small ones usually cause no symptoms. Larger cysts may cause a dull ache, swelling or a feeling of heaviness in the scrotum.

Other common lumps can feel similar. The NHS notes that most testicle lumps are due to less serious causes such as a fluid build-up or swollen veins (varicocele). MedlinePlus lists hydrocele, varicocele, hematocele and abscess among other benign scrotal masses. Telling them apart is a job for an examination and, often, a scan.

An epididymal cyst is not cancer. Cleveland Clinic says there is no evidence that these cysts can turn into cancer, and they do not raise the risk of testicular cancer. Having one also does not stop you from developing other, unrelated lumps later.

The reason doctors still want to examine every new lump is that the cause is not always clear by touch. MedlinePlus notes that testicular cancer is usually painless and most often affects people aged 15 to 40, and that a lump which persists should be rechecked even after an earlier reassuring opinion. Once a scan has confirmed a simple cyst beside a normal testicle, many people find it easier to watch for change rather than worry about the lump itself.

A doctor will usually ask about your symptoms and examine you. The NHS describes shining a light through the scrotum to check for fluid; Cleveland Clinic explains that a fluid-filled cyst lets light through, unlike a solid lump.

A scrotal ultrasound is the usual test to confirm what the lump is. It uses sound waves to show the fine details of the lump, helping the doctor see whether it is a fluid-filled cyst beside the testicle or something that needs a different approach. If you have pain, a urine test may be used to look for infection or inflammation.

Usually not. Cleveland Clinic says no treatment is needed if a spermatocele does not cause pain or discomfort, and the NHS notes that a lump that is not causing problems or getting worse may need no treatment. Cleveland Clinic notes that they do not usually go away on their own.

If a cyst is large or causes ongoing pain, a urologist may discuss options. The NHS says painful or very large lumps may need a specialist to drain, shrink or remove them. Cleveland Clinic describes spermatocelectomy, a surgery to remove the cyst, as generally safe and routine. It also cautions that surgery can block the epididymis, which could affect fertility, so this is worth discussing if you may want children in future. The cyst itself does not cause infertility.

Bring your scan report, and write down when you first noticed the lump and any changes since.

• Is this definitely an epididymal cyst, and is the testicle itself normal on the scan?
• How big is it, and does it need any follow-up check?
• What changes in size, pain or feel should make me come back?
• Is my discomfort likely to be from the cyst, or could something else be causing it?
• If I consider surgery, what are the risks, including to fertility, and what happens if I do nothing?

On SameCase, patients and verified doctors share de-identified cases. Reading how others with a lump above the testicle described their symptoms, which checks they had and what they asked a urologist can help you prepare clearer questions. Other people's cases cannot tell you what your lump is; an examination and your own care team can.