What Causes Yellow Dots And Growth Between Bones On Chest?

I'm a 22 yr. old male. I've had a growth between my bones in my chest for the past few years now. Several doctors said different things "a muscle tear - fatty growth" its hard, and it started out small, but grew, doesn't grow anymore. I've had several yellow dots in the same area on the same pectoral. I'm an athlete but i dont do vigorous weight lifting. What could the yellow dots be as well as the growth?