I have a knot on my left rib cage. I recently had back surgery about 2 weeks ago. I thought I had the crud. I went and got a shot, antibiotics, and cold medicine. I have been getting worse. I wake up in the night and can't breath. I went to the er and had an xray and they said it didn't show up anything and sent me home to figure out what was wrong with me. I am 37 years old. I have a very strong family history of cancer. And I am a smoker. I am scheduled to have an ultrasound tomorrow.