What is an epididymal cyst?
The epididymis is a coiled tube that sits above and behind the testicle and connects it to the sperm duct (vas deferens). A small fluid-filled sac can form inside it. This is an epididymal cyst. When the fluid also contains sperm, the cyst is called a spermatocele. Both are benign, which means they are not cancer.
These cysts occur in young children as well as teenagers. In a large study of children who had a scrotal ultrasound, a cyst was found in about 2% of them. In that study, cysts measured from 2 to 35 mm. Most sit in the head of the epididymis, so they are felt at the top of the testicle.
Symptoms
- a soft, smooth lump above the testicle that can be felt separately from it,
- usually no pain,
- with larger cysts, swelling of the scrotum and sometimes pain.
Most cysts cause no symptoms and are found during a routine checkup or when a teenager examines himself.
Important: a firm, painless lump in the testicle itself is not an epididymal cyst. Such a lump can be a testicular tumor and should be shown to a pediatric urologist without delay. The absence of pain is no reason to wait.
Tests
The doctor feels the scrotum and determines whether the lump is in the testicle or in the epididymis. A scrotal ultrasound is done to confirm the diagnosis and rule out other conditions. It shows the cyst’s size and location and helps tell it apart from tumors, a hydrocele and a varicocele.
Treatment
- A small, painless cyst is not treated but watched. In a study of children, some cysts disappeared completely during follow-up and others shrank.
- Surgery is discussed if the cyst grows, causes pain, or if its nature is unclear on ultrasound. The cyst is removed during the operation. Because the tubules of the epididymis are very fine, surgery is done carefully under magnification.
The cyst itself does not affect the ability to have children later.
Follow-up and self-exam
A cyst can grow, or more cysts can appear, so checkups at the times the doctor sets and a repeat ultrasound when needed are important. Teenagers are encouraged to examine their testicles once a month; the doctor can show your son how to do it.
When to see a doctor
- sudden, severe pain in the testicle or scrotum: this could be testicular torsion, so seek emergency care right away,
- a new firm lump in the testicle itself: even if it does not hurt, do not wait for a scheduled visit,
- a cyst that grows or starts to hurt: have it checked without waiting for the next scheduled visit.
When to seek urgent care
If any of the following is present, do not wait for a routine appointment: call the doctor or go to the nearest emergency department.
- Sudden, severe pain in the testicle or scrotum (testicular torsion must be ruled out)
- A firm, painless lump in the testicle itself (prompt evaluation to rule out a tumor)
Call your local emergency number (112 in Europe, 911 in North America)
Note for pediatricians and family doctors
Epididymal cysts and spermatoceles are benign fluid-filled lesions of the epididymis; in a spermatocele the fluid also contains sperm. In a retrospective review of 6,338 pediatric scrotal ultrasounds, cysts were found in 2.26%; of the 143 boys, 95 were prepubertal and 48 postpubertal, cyst size ranged from 2 to 35 mm, most were detected through a routine physical exam (such cysts typically arise from the epididymal head). During follow-up, 12 cysts resolved, 6 shrank and 2 grew; all children were managed conservatively except one (excision for a progressively enlarging mass). Surgery is considered for symptomatic or growing cysts and for lesions of uncertain nature, ideally under magnification to protect the epididymal tubules. Ultrasound helps distinguish a cyst from cystic tumors of the epididymis. Any palpable mass within the testicular parenchyma must not be assumed to be a cyst and needs prompt evaluation until a tumor is ruled out.
What happens at the visit?
- We carefully examine the scrotum and determine whether the lump is in the testicle itself or in the epididymis.
- We perform a scrotal ultrasound to assess the cyst’s size and location and any other findings (hydrocele, varicocele).
- We explain the follow-up plan and teach teenagers how to examine their own testicles.
Frequently asked questions
Can the cyst go away on its own?
Yes, sometimes. In one study of children, some cysts disappeared completely during follow-up and others shrank. A small number may grow, which is why follow-up matters.
How can a cyst be told apart from a testicular tumor?
A cyst is usually a soft lump felt above the testicle and separate from it. A firm lump in the testicle itself needs its own prompt evaluation. The doctor tells them apart with an exam and ultrasound; do not try to sort this out at home.
If surgery is done, could it affect fertility later?
The epididymis is made of very fine tubules. That is why surgery is done only when truly needed, and carefully, under magnification, to protect those tubules.
Related topics
Sources
- Cai W et al. Epididymal cysts in children: frequency, clinical characteristics, and management strategies. Front Pediatr, 2024.
- Children’s Hospital of Philadelphia. Epididymal cyst and spermatocele.
- Ann & Robert H. Lurie Children’s Hospital of Chicago. Spermatocele (epididymal cyst).
- NHS. Testicle lumps and swellings.
This information is for educational purposes and does not replace medical advice. Decisions about your child’s treatment are made with the doctor after an examination.
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