Im 17 years old and I have hip dysplasia with snapping hip over it. Can you think of anything that would help me lessin the pain Im in?

My husband broke his ribs about 5 years ago, after they healed we discovered a lump at the bottom of his right ribcage where he had broken them, it has been there for quit some time and has gotten bigger.  As he gains weight it gets bigger, but as he looses weight it gets smaller, it looks like a oversized fat roll compared to the other one, he says there is no pain, it doesn't bother him when I push on it and ask him if it hurts, we went and got x-rays, they turned out fine and even got an MRI, and they didn't find anything, this was about a year ago, so is this something that we should worry about or what?