I have a hard lump on and above on my clavicle, right side. It does not hurt and is the size of a huge marble. It literally " appeared" all at once. Nothing showed on the x-ray at the doctors nor chiropractors office. Medical doctor says only a cat scan will tell us anything. Chiropractor says only an MRI will tell us. I really dont want to get the cat scan because of the dye and all the radiation. I read different posts but nobody seems to know what this is??