A harmless fluid-filled cyst on the epididymis: smooth, round, clearly separate from the testicle, usually painless - benign, not cancer, does not become cancer, and usually needs no treatment beyond confirmation by exam and ultrasound.
The exceptions: one that grows large enough to ache or drag can be removed or drained (draining tends to refill, and surgery carries a small duct risk on that side - reserved for genuine bother). The standing rule overrides: any new scrotal lump gets examined - the diagnosis comes from the exam, not from guessing, and once it is named you can stop worrying.
What to do
Common questions
What is a spermatocele?
A spermatocele is a small fluid-filled cyst that grows on the epididymis - the coiled tube behind the testicle that stores sperm - typically containing fluid and sperm cells. It is benign, common, and not cancer, and it does not turn into cancer. The signature feel: a smooth, round, well-defined lump that sits ABOVE and behind the testicle, clearly separate from it - distinct from the testicle itself, which is part of the reassurance - usually painless, found by accident in the shower. It does not usually affect fertility, and most need no treatment at all: the standard management is simply confirming the diagnosis (an exam, sometimes an ultrasound) and leaving it alone. The exceptions: one that grows large enough to ache, drag, or bother can be removed surgically or drained - though draining tends to refill, and surgery carries a small fertility-duct risk on that side, so treatment is reserved for genuine bother. The standing rule that overrides everything: ANY new scrotal lump gets examined, because the serious lookalikes are diagnosed by exam and ultrasound, not by guessing - once the doctor says "spermatocele," you can stop worrying. Pymander, a free AI doctor available 24/7 by text, can help you describe what you are feeling.