I Have A 2-inch Lump On The Inner Side Of

I have a 2-inch lump on the inner side of my left elbow. I've had it for about 4years. It wasn't painful unless I bumped, at first. It gradually became more and more painful. Now, it's very tender and I get excruciating, shooting pain there, out of the blue. When I asked my primary care Dr.when I was there for my Colon problems, he brushed it off as a fatty deposit. It sounded reasonable at the time, but now I'm concerned about the pain, especially since I take both Kadian (Morphine) and generic Norco for my chronic abdominal pain (I've had a total colectomy) and get no relief in my elbow. I'll make an appointment with my new Primary Dr.soon,but I would appreciate any advice in the meantime. Thank you for your help, B.Carver