Hi Sam, I was doing a testicular exam a couple of weeks ago and I came across a fairly sizeable lump at the top of my scrotum just below the base of my Penis, it is located at top top of my scrotum on the right hand side, I ve been reading into it and I think it may be a epididymis cyst but I m not sure, what other things could this be because it s a pretty large lump that s visible, it s almost like a 3rd testicle in size, it s slightly smaller (PS. none sexually active 16 year old)