This is weird and embarrassing. Im 15 and a guy. Im not fat at all. In fact my parents complain that I'm too skinny, which is ridiculous but w/e. Anyway I noticed a while ago that one of my nipples was sore. Then I found out that this can happen to guys when they're going through puberty so I didn't worry about it. However today when poking at the sore area I discovered for the first time that there is a very deffanite lump behind my nipple. This is almost funny its so gross. But not funny at all if it means I have cancer. I heard just recently that men can get "breast cancer" which ironically I laughed at. I figured this happened to people with a little extra weight who have kinda man boobs which I don't really have but I guess I have a tiny but of extra fat in that area. So anyway, my nipple has been sore for at least three weeks and I don't feel sick or anything so I guess that's a good sign. But I am very worried. Is this cancer? And if its not what else could it be?