A Radiologist will read the images and determine if it is gynecomastia or something else. It could be
hormone related. Sometimes medications can cause
gynecomastia.....certain antidepressants, cimetidine, antiandrogens, diazepam, digitalis, marijuana, and certain steroids. At your age, it could also be an increase in hormones.....
I think seeing a specialist is a good suggestion, for your peace of mind!