What Could Be The Brown Raised Thing On Head Of Penis?

I've had a Brown slightly raised and oddly shaped stain looking thing on the head of my penis, it started many years ago when I was little, I'm 18 now. When it first came out it was small, over the years it has gotten bigger and looks as if its spreading, also at a point where it ends there's a small bump, the bump used to have a black head looking thing which after messing with it for a while went away, but the bump remained. After a week the black head thing came back and once again I messed with out and it went away, now its just the bump again. Can you tell me what either of these things are and is there anyway to get rid of them?