question: I have been diagnosed with a calcification below the collarbone above the 1st rib and will be seeing a Rhuemetologist. What exactly is a calcification? I had rectal cancer in 2001, stage II, lower anterior resection and 6 months chemo. My oncologist is referring me over, should I be concerned, I have discomfort in my chest in that area and have been having low blood pressure with fainting type dizziness.