Hello. I m 21 and I discovered a small lump on my left rib cage a few months ago. It s painless, with the exception of over touching it or being a little tender after work. (I stock Freight) on what seems to be the bottom rib (mid way down) It can be moved a little bit, and disappears when I lie down. I just went to the quick care and she said it was nothing, but It was a quick evaluation and I still worry.