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

A spermatocele, often referred to by UK patients as an epididymal cyst, is a fluid-filled sac that develops in the epididymis. The epididymis is the coiled tube located at the back of each testicle that stores and transports sperm. Unlike some other scrotal lumps, a spermatocele is typically painless and benign, meaning it is not cancerous.

These cysts contain a milky or clear fluid that may include sperm. While they can be alarming when first discovered during a self-examination, they are incredibly common and often remain small and asymptomatic. According to NHS clinical pathways, they do not usually require aggressive treatment unless they cause physical distress or grow to a size that interferes with daily activity.

Most men with a spermatocele do not experience any symptoms at all. The cyst is frequently found incidentally during a routine check-up or a personal testicular self-examination. However, if symptoms do occur, they may include:

• A distinct, smooth, and firm lump felt at the top or back of the testicle.
• A general sense of heaviness or fullness in the affected side of the scrotum.
• A dull ache or pressure, particularly if the cyst is large enough to press against other structures.
• Redness or swelling of the scrotum (though this is rare and may indicate infection rather than a simple cyst).

It is important to note that a spermatocele is usually separate from the testicle itself; you should be able to feel the testicle as a distinct entity beneath the cyst.

The exact cause of spermatoceles remains largely unknown in the medical community. However, several theories suggest they may result from a blockage in one of the many tubes within the epididymis that transport sperm. This blockage causes fluid to back up and form a cyst.

While they can appear at any age, they are most frequently diagnosed in men between the ages of 20 and 50. Potential risk factors or associations include:

• History of trauma or injury to the scrotum.
• Previous episodes of inflammation or infection (epididymitis).
• Exposure to certain medications in utero (such as diethylstilbestrol), although this is now rare in the UK.

Importantly, having a spermatocele does not increase your risk of developing testicular cancer, nor does it typically impair your ability to father children.

In the UK, the diagnostic process follows NICE (National Institute for Health and Care Excellence) guidelines for investigating scrotal lumps. The primary goal is to differentiate benign cysts from more serious conditions like testicular cancer or inguinal hernias.

Physical Examination

A GP will perform a physical examination of the scrotum. They may use 'transillumination,' which involves shining a light through the scrotum. Because spermatoceles are fluid-filled, the light will usually shine through them, whereas a solid tumour would block the light.

Scrotal Ultrasound

If there is any doubt about the nature of the lump, the GP will refer you for a scrotal ultrasound. This is a painless procedure that uses sound waves to create a clear image of the internal structures of the scrotum. It is the gold standard for confirming a spermatocele and ensuring the testicle itself is healthy.

Finding a lump in your scrotum can be a source of significant anxiety. While many lumps are benign, it is essential to get any new abnormality checked by a healthcare professional as soon as possible. You can speak to a GP online to discuss your symptoms, receive advice on how to perform a correct self-examination, and understand the next steps for diagnosis.

An online doctor can provide a calm, clinical assessment of your history and, if necessary, facilitate a referral for a physical examination or a private ultrasound scan. This is an efficient way to address your concerns without the wait times often associated with local surgeries, helping you gain peace of mind or start the appropriate care pathway quickly.

If your spermatocele is small and not causing pain, the most common recommendation is 'watchful waiting.' This involves monitoring the cyst for any changes in size or sensation. Most spermatoceles do not disappear on their own but stay the same size for years.

If the cyst causes pain or grows very large, treatment options include:

• Pain Management: Over-the-counter paracetamol or ibuprofen may be suggested to manage occasional discomfort.
• Spermatocelectomy: This is a surgical procedure to remove the cyst. It is usually performed as a day case under general or local anaesthetic. While effective, there is a small risk of damage to the epididymis or the vas deferens, which could affect fertility.
• Aspiration and Sclerotherapy: A needle is used to drain the fluid, and a sclerosing agent is injected to prevent the cyst from refilling. This is less common due to a higher risk of recurrence compared to surgery.