Why is my rib cage deformed?

A bunch of half-dollar sized lumps under my rib cage on both sides - why?

• I've gone to the doctor a couple times, and am still due for bloodwork two more times, as well as a chest x-ray. Anyway, I have a low-grade fever on and off, and that's... essentially it. I'm also 19 years old. I've noticed, tucked under both sides of my rib cage, lumps about the size of a half-dollar that are quite hard and painless - they move up and down, and don't hurt. When they slide up and down the bone, I can hear it, as if it's hitting the bone. My doctor was basically like "Well... I don't know... I really don't think that's anything..." I also have much smaller, pea-sized lumps on my spine here and there. He also said those were 'nothing.' ... What do you guys think...?

• Answer:

  Get a biopsy done of the lump in question.