It might be a bony tumor (don't worry I don't mean like a cancerous tumor) but I have a bump sort of like that and it makes my shoulder hurt terribley, but I got it checked out and it turned out to be an osteokondroma (I think that how you spell it) but all it is is a bony outgrowth due to a recent increase of growth. Sometimes they have to take it out, but not often. Have you asked your doctor about it?
