Epididymal cysts are fluid filled swellings connected with the epididymis that occur in males. If the fluid contains sperm, it is called a spermatocele.
They arise from the collecting tubules of the epididymis, as a thin-walled cyst containing watery or slightly milky fluid.
A swelling in the scrotum located above and behind the testes, thus some patients attend saying they have developed a third testis. Cysts may be small, multiple, and are frequently bilateral and transilluminate brightly.
As the cysts are totally benign, they are best left alone. Surgery to remove the cyst(s) risks damaging the spermatic pathway, such that bilateral operations can cause sterility, and more conservative removal often leads to recurrence.