An epididymal cyst is a harmless little fluid-filled growth on a man's testicle (testis). They are quite common and don't usually require treatment. Many men feel them and are concerned they have testicular cancer, but a doctor can usually tell the difference.
What is an epididymal cyst?
A cyst is just any small bulge that is filled with fluid. Cysts can grow almost anywhere in the body.
The epididymis is the name of the little tubes just above the testicle (testis). This picture shows where the epididymis is:
So an epididymal cyst is a harmless growth that grows from the tubes just around a man's testicle.
Who gets epididymal cysts?
Men are most likely to develop these cysts around the age of 40. Children rarely get them before they become teenagers. It's hard to give an exact percentage of boys or men who have epididymal cysts because most people who have them don't even know it! But some studies have shown that about 1 in 6 men have them.
Epididymal cyst symptoms
- A soft, slightly squidgy lump at the top or bottom of your testicle (testis).
- They are usually entirely pain free.
- They do not get infected or affect your ability to pass urine or to ejaculate.
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What else could it be?
- Spermatocele: this is a cyst which feels like an epididymal cyst but it is filled with sperm (semen).
- Inflammation: some illnesses cause a thickening of the epididymis and surrounding structures which can feel like an epididymal cyst.
- Hydrocele: this is caused by a collection of fluid in the scrotum.
- Varicocele: this is like varicose veins of the small veins next to one testicle (testis) or both testes. It is usually described as feeling like a 'wriggling bag of worms'.
- Lipoma: this is a fatty lump which can sometimes cause difficulty because it can be felt separate from the testicle, just like an epididymal cyst.
Do I need any tests?
- Usually they are quite typical in the way they feel and a doctor can confidently reassure you.
- If the doctor isn't quite sure what the lump is, they could arrange an ultrasound scan of your scrotum.
Are there any associated illnesses?
Most men with epididymal cysts are quite healthy. There are some quite rare conditions that can cause epididymal cysts:
- Cystic fibrosis: an inherited illness in which there are cysts in the lungs, pancreas and other areas of the body.
- Polycystic kidney disease: an inherited condition in which cysts develop in the kidneys and other parts of the body.
What is the treatment for epididymal cysts?
- If the cyst is small and causing no problems then all you need to do is keep an eye on it and see a doctor if it gets bigger or painful.
- Children do not usually need treatment because most cysts disappear by themselves. However, surgical removal may be necessary if they become painful or don't start to shrink.
- Large or painful cysts can be removed surgically.
What problems can epididymal cysts cause?
- Usually epididymal cysts don't cause any problems at all. But occasionally they can twist around and become very painful. This happens pretty quickly: within about half an hour. It is really painful and usually needs surgery to untwist it and remove it.
Further reading and references
Niedzielski J, Miodek M, Krakos M; Epididymal cysts in childhood - conservative or surgical approach? Pol Przegl Chir. 2012 Aug84(8):406-10. doi: 10.2478/v10035-012-0068-2.
Valentino M, Bertolotto M, Ruggirello M, et al; Cystic lesions and scrotal fluid collections in adults: Ultrasound findings. J Ultrasound. 2011 Dec14(4):208-15. doi: 10.1016/j.jus.2011.10.008. Epub 2011 Nov 4.
Lee JC, Bhatt S, Dogra VS; Imaging of the epididymis. Ultrasound Q. 2008 Mar24(1):3-16.