I have had a lump on my right side of my stomach for about 5 months now. I don't think much of it and thought I pulled something. I ended up going to the er to see if they can see what this was???? They had no idea what it was? They gave me an ultrasound and saw the lump but couldn't figure out what it could be? I have been having annoying pain on my right side. I feel like I might have a floating rib as well. I always have to stretch to ease the pain. When I feel the lump it slides around and is about the size of a baseball. It's driving me crazy. Any ideas what this could be??????