A spermatocele or epididymal cyst is a sperm filled cyst in the epididymis at the top end of the testicle. The epididymis consists of hundreds of tiny tubules that collect sperm from the testes, and join up to lead into the vas deferens, which takes the sperm to the seminal vesicle (sperm storage sac) and penis. Cyst formation may follow an injury to the testicle or a vasectomy, but often appears for no apparent reason.
A lump is felt at the top of the testicle, but separate from the testicle. It is usually painless, but may become painful if injured or infected. Bleeding into the cyst after an injury may cause a sudden increase in size and pain.
It is usually a clinical diagnosis, but an ultrasound scan can confirm the diagnosis if there is any concern.
No treatment is necessary unless the patient finds the cyst painful, uncomfortable or worrying, when it can be drained or removed.