I have a swelling on top of my left rib cage, just under my pectoral area. Roughly the size and shape of a small banana, stretching from about 7-8 inches below the left armpit, to about 3 inches below and a little inboad of my left nipple . It s been there, and getting larger, for about six months and occasionally hurts. It s about 1 1/2 to 2 inches thick and maybe 7 inches in length.