For the last several months I have had a swelling on both sides of my neck above my collar bone. There always seems to be some kind of pressure in my neck, almost a numbing sensation. Just recently I noticed there was a slight swelling on the tip of collarbone which seems to be getting slightly larger. I have had half of my throid removed about six years or more ago. I've also been taking tyroid medication for many years, even prior to the surgery. It is difficult to diagnose yourself but have read about the thymus gland on the internet. Does anyone know anything about the type of symptons you may have if there is a problem with your thymus gland, could this be cancer?