Im a 18 year old male with no history of cancer in the family. Recently, I discovered a bump, or lump, at the base of my spine. It isnt a cyst. It's under the skin and has never had any sort of discharge. The bump has always been there, at least for the past few years. It just has been there. Within the past several days though, it has become painful to sit down. I've had no problems passing excrement.The pain is a sharp jab that quickly declines if I don't move.My first thought was a that my coccyx was chipped somehow.A description of the bump itself is that it is located within the butt crack, roughly 2-3 inches above the anus. I've tried to see if there is any sort of discoloration on the skin but found none. So I'm quite confused.