This is where a part of the epididymis becomes distended with fluid that contains sperm.
What Causes An Epididymal Cyst?
Scarring of any part of the epididymis can cause it to become obstructed which in turn causes the swelling with fluid and sperm called an epididymal cyst.
Diagnosis
Diagnosis is made by:
Examination of the scrotum. The cyst can be felt attached to the epididymis. Also the testis can be felt which is not the case in a hydrocele.
If the cyst is not bothering you it can be left alone. Epididymal cysts are universally non-cancerous. Leaving them alone will not cause it to become cancerous.