Epididymal cysts. Ultrasound scan of epididymal cysts (three black areas, centre) on the testicle of a 42-year-old man. Epididymal cysts are fluid- filled sacs that form along the epididymis, a coiled tube that stores and carries sperm away from the testis. Epididymal cysts can be tender but are completly benign. The fluid in the cysts can be removed through a tiny needle. If the cysts become larger than normal, they can be surgically removed.