Spermatocele (Epididymal Cysts): Symptoms, Causes, and Treatment in the UK

A spermatocele, often referred to as an epididymal cyst, is a fluid-filled sac that grows in the epididymis. The epididymis is the coiled tube located at the back of each testicle that stores and transports sperm. While the term 'testicular lump' can be alarming, a spermatocele is benign, meaning it is not cancerous. These cysts are typically filled with clear or milky fluid that may contain sperm.

In the UK, spermatoceles are quite common, affecting roughly 1 in 3 men at some point in their lives, often discovered incidentally during a self-examination or a routine check-up. They vary in size from a few millimetres to several centimetres and are usually smooth and round when felt through the scrotal skin.

Most spermatoceles do not cause any symptoms at all. You might only notice them as a firm, smooth lump located at the top or back of the testicle. Unlike some other scrotal conditions, they are generally painless.

However, if the cyst grows larger, you may experience:

• A feeling of heaviness or 'dragging' in the affected testicle.
• General discomfort or a dull ache in the scrotum.
• Physical swelling that is visible through the skin.
• Pressure at the base of the penis.

Because these cysts are separate from the testicle itself, you can usually feel a clear distinction between the lump and the testis. If the lump feels like it is part of the testicle wall, this requires more urgent medical attention.

The exact cause of a spermatocele remains unclear. Medical consensus suggests they may occur due to a blockage in one of the many tubes within the epididymis that transport sperm. This blockage causes the fluid to collect and form a cyst.

While they can happen to any man, certain factors may increase the likelihood of developing one:

• Age: They are most frequently diagnosed in men between the ages of 20 and 50.
• Trauma: Previous injury to the scrotum or inflammation (such as epididymitis) may play a role.
• Maternal DES exposure: There is some evidence that men whose mothers took the drug diethylstilboestrol (DES) during pregnancy to prevent miscarriage may have a higher risk, though this drug has not been used in the UK since the 1970s.

Following NHS and NICE guidance, any man who discovers a new lump in his scrotum should see a GP. During a consultation, the doctor will perform a physical examination, potentially using a technique called transillumination. This involves shining a bright light through the scrotum; because spermatoceles are fluid-filled, the light will show through them, whereas a solid mass (which could indicate a tumour) will block the light.

To confirm the diagnosis, your GP may refer you for a scrotal ultrasound. This is a painless imaging test that uses sound waves to create a picture of the internal structures of the scrotum. It is the gold-standard method for distinguishing between a harmless cyst and other conditions like a hydrocele, varicocele, or testicular cancer.

If a spermatocele is small and not causing pain, the standard approach is 'watchful waiting'. This means no active treatment is required, but you should continue to monitor it during your regular self-examinations. Spermatoceles do not usually disappear on their own, but they often remain the same size for years.

If the cyst causes significant pain or grows so large that it interferes with daily life, surgical options may be considered, such as:

• Spermatocelectomy: A surgical procedure to remove the cyst from the epididymis. This is typically done as a day case under general or local anaesthetic.
• Sclerotherapy: A less common procedure where fluid is drained and an irritating agent is injected to cause the sac to scar and close. However, this carries a higher risk of recurrence and damage to the epididymis.

It is important to note that surgery on the epididymis can occasionally lead to blockages that affect fertility. For this reason, doctors in the UK usually advise against surgery for men who still wish to father children unless absolutely necessary.

If you have discovered a lump but are hesitant to visit a surgery in person, you can speak to a GP online for an initial assessment. An online doctor can discuss your symptoms, review the history of the lump, and provide guidance on the next steps.

Using a private online doctor service can be a fast way to get professional reassurance. If the doctor suspects a spermatocele, they can advise you on how to monitor it. If they have any concerns that the lump requires further investigation, they can issue a referral letter for a private ultrasound or advise you on how to proceed with the NHS. Treatment for spermatocele UK pathways often begin with this simple conversation to rule out more serious pathology.

Health professionals recommend that men perform a testicular self-examination (TSE) once a month. The best time is after a warm bath or shower when the scrotal skin is relaxed. Gently roll each testicle between your thumb and fingers, feeling for any changes in size, shape, or consistency. Knowing what is 'normal' for you makes it much easier to spot a cyst early and seek medical advice without delay.