question: I had an episode of rapid heartbeat two weeks ago, my heart dr. did several tests and sent me home with a beta blocker to take every day, and also i am wearing a heart monitor...since i have been wearing the heart monitor, (one week 1/2) i noticed a small area on my right collarbone that looked a little puffy so i felt it and it feels like a small marble moving around...my dr. looked at it and put me on antibiotics...i had a chest xray and chest c/t scan at the hospital march 2nd...my dr. was going to do an xray, but after i told him i had one march 2nd he said ok then he doesnt need to do another one...from what i am reading it sounds like lumps/marbles could be cancerous and i  am extremely scared now...what do you think it most likely is? i was sick in feb. with congestion/cold symptoms???