Question: Age 20

This is about an epididymal cyst which I believe is large enough to be called spermatocele. I am 20 years old, have abstained from sex, have had this cyst growing on the left testicle for roughly five years. For 6 months now, it appears darker than it ever was. Shining a light on it, it even appears nearly dark grey. It is a large mass. The right testicle has one growing too. There is not usually any pain apart from a dull ache, which doesn't happen often. I don't think this sort of thing is well documented and I was worried about gangrene or epididymitis. What could this be, what is the risk factor/complications?

When 14 years old, saw GP about hair follicle bumps on penis, was told it is normal. Told GP about scrotum itchyness which was very intense for a while. The hydrocortisone was recommended but I did not use it. Eventually the itchyness subsided anyway. Now I am OK. At the same time, I was scratching my penis shaft a lot and I noticed a flat skin line appear up the shaft, wider nearer the scrotum (fades into the scrotum) and thinner nearer the head, (nearly same color as scrotum, a pink-ish color). Recently I saw a doctor about the skin and apparently it looks normal. Most recent consultation with GP was positive, no apparent problems, received no answer when I asked him about the color of the epididymal cysts. He wants me to go back and see him about anxiety related issues.

Other: believed to have eczema in belly button since age of 12. Responds to cream. Penis/scrotum skin color does not change with cream (was prescribed more hydrocortisone about 6 months ago for neck and backside, and decided to apply to scrotum and penis as well, but the doctor did not know about that. Scrotum became itchy as a result and I scratched a lot, noticed the color change in cysts as mentioned but whether that was a coincidence, I do not know.