What are the lumps on my shoulder?

when i got out of the shower today, i found myself looking in the mirror at my right shoulder. i found that when i put my palm flat on the lower part of my back (so my shoulder is protruding) i have small lumps on my shoulder. when i probe them with my left hand, they start to hurt and when i put my right hand back down and i'm standing normally, the lumps are gone. when i replace my right hand on my lower back sometimes they have moved or are gone. they are on my shoulder bone. right by the socket. i don't feel like its a form of cancer. it's too far over to be. my brother said he has the same problem except on the left side. He feels like it may be some sort of parasite, but that its a symbiotic relationship--no one is hurt until they decide to probe around.