I have soft tissue swelling or puffiness at the base of both sides of my neck, near the collar bone. There is no pain or discomfort; no rash or redness. It feels like fatty tissue, but I don't have any weight gain and am not really overweight. If I relax my shoulders, it almost disappears, but if I raise my arms or shoulders, it puffs up. I first noticed it a couple of months back while brushing my teeth. I am a 46 year old male, about 5' 9.5", and weigh about 183 pounds. I don't have any major medical problems except I have recently had kidney stones.