I had (possibly still have?) an enlarged vein just above my left ball that I noticed when I was 15 (ie. 11 years ago) and was scared of, assuming the worst. Saw a doctor, was told it could be treated if I wanted. I just left it alone and although it would ache from time to time it has never been a problem. Moral of the story - scrotal weirdness can be all sorts of things, not necessarily serious.