What is an epididymal cyst?

An epididymal cyst is a benign fluid-filled sac that forms near the epididymis, typically as a result of prior injury or inflammation of the epididymal tubule. The fluid inside contains spermatozoa or seminal fluid. It is completely benign and not cancerous.

What are the symptoms of an epididymal cyst?

Most epididymal cysts are asymptomatic and are discovered incidentally during self-examination in the shower as a painless scrotal swelling. They are found incidentally in 20–40% of scrotal ultrasound studies. Some patients may experience mild scrotal discomfort.

Is an epididymal cyst dangerous or cancerous?

No. An epididymal cyst is a completely benign lesion and does not become cancerous. It does not pose a serious health risk, though it can cause discomfort if it grows large.

Does an epididymal cyst go away on its own?

It depends on the size. Cysts smaller than 10 mm have a 95% chance of resolving naturally within 3 years. Cysts between 11–20 mm have a 66% chance of natural resolution. Cysts larger than 20 mm have 0% chance of resolving on their own and may require intervention.

Can surgery for an epididymal cyst affect fertility?

Yes. Surgical excision of an epididymal cyst carries a risk of damage to the epididymis, which can potentially affect fertility. For this reason, surgery is only considered as a last resort for large symptomatic cysts that have not responded to other treatments.

Epididymal Cyst: What to Do About It

Last updated: May 18, 2026

Soarawee Weerasopone, Urologist

Bangkok hospital Headquarter, Bangkok

Samitivej Sriracha hospital, Chonburi

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Epididymal cyst is one of the most common testicular-related issues at my urology office. It was defined as an encysted structure closures the epididymitis which is literally described as a result from prior injuries or inflammations of the epididymis tubule. These meaning that epididymal cyst are absolutely a benign lesion.

The symptom will usually present as incidentally self-examination painless scrotal swelling during taking a shower.

Natural history of Epididymal cyst

While mostly asymptomatic, 20-40% are incidentally found on scrotal ultrasound. The natural history varies from spontaneous resolution, stable, or slow growing over time. It is highly recommended not to intervene with any asymptomatic epididymal cyst.

Less than 10 mm – Conservative treatment with 95% natural resolution within 3 years.
11-20 mm – Conservative treatment with 66% natural resolution within 3 years. Needle aspiration for symptomatic patients.
21-50 mm – 0% natural resolution within 3 years. Needle aspiration for symptomatic patients. Surgical excision is last resort due to fertility risk.

Surgical excision will be considered in more than 2 cm symptomatic epididymal cyst.

All I can say is, don’t be panic with the cyst. See you in next article!

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Frequently Asked Questions

Q1: Is an epididymal cyst dangerous?

No. An epididymal cyst is a benign (non-cancerous) lesion. It contains spermatozoa or seminal fluid and forms as a result of prior injury or inflammation of the epididymis tubule. The vast majority of epididymal cysts are harmless and do not require treatment unless they cause significant discomfort or grow to a large size.

Q2: Do epididymal cysts go away on their own?

Many epididymal cysts resolve spontaneously, particularly smaller ones. Cysts less than 10 mm have a 95% chance of natural resolution within 3 years. Cysts between 11-20 mm have a 66% chance of resolution. However, larger cysts of 21-50 mm have essentially 0% chance of natural resolution and may require intervention if symptomatic.

Q3: When does an epididymal cyst need treatment?

Treatment is generally recommended only when the cyst causes significant symptoms such as persistent scrotal pain or discomfort, or when the cyst is large and growing. Asymptomatic cysts are typically managed conservatively. Needle aspiration is an option for symptomatic cysts, while surgical excision is reserved as a last resort due to the risk of fertility impairment.

Q4: Can an epididymal cyst affect fertility?

An untreated asymptomatic epididymal cyst does not typically affect fertility. However, surgical excision carries a risk of damaging the epididymis and impairing sperm transport. This is why surgery is considered only as a last resort for large, symptomatic cysts.

Q5: How is an epididymal cyst diagnosed?

Epididymal cysts are most commonly discovered incidentally during scrotal self-examination or detected on scrotal ultrasound. Ultrasound is the gold standard imaging tool for diagnosing and characterizing epididymal cysts, confirming their benign nature and measuring their size. A urologist will assess the findings and recommend the appropriate management plan.

If you have discovered a scrotal lump or been told you have an epididymal cyst and would like a specialist evaluation, Dr. Soarawee Weerasopone offers consultations at Bangkok Hospital Headquarters. Book a Consultation.

Disclaimer: This content is written and reviewed by Dr. Soarawee Weerasopone, a board-certified urologist at Bangkok Hospital Headquarters. It is intended for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before starting any medical treatment.

Medically written & reviewed by: Dr. Soarawee Weerasopone (Dr. Pom) — Board-Certified Urologist, Bangkok Hospital Headquarters. International Fellow: Baylor College of Medicine (USA) · Juntendo University (Japan) · Chang Gung Memorial Hospital (Taiwan).

Dr. Soarawee Weerasopone

Dr. Soarawee Weerasopone (Dr. Pom) is a board-certified urologist at Bangkok Hospital Headquarters, specializing in Men’s Health, Robotic Surgery (Da Vinci System), and Kidney Stone treatment. He has completed international fellowships at Baylor College of Medicine (USA), Juntendo University Hospital (Japan), and Chang Gung Memorial Hospital (Taiwan). All medical content on this site is written and reviewed by Dr. Soarawee based on his clinical experience and international training.