A spermatocele, or epididymal cyst, is a small, harmless lump that occurs on top of one of the testes inside the scrotum. It occurs in the epididymis, the thin tube that connects the testis with the vas deferens.

An epididymal cyst is filled with clear fluid, whereas a spermatocele also contains dead sperm cells. They are usually asymptomatic and are only found on self-examination or during a routine physical exam.

A scrotal ultrasound will usually be ordered to rule out any other conditions. Usually, they are not treated, however, if they grow or cause pain, surgical options will be discussed.