Hi. My son is 29 and a smoker. Last week, he noticed a marble-sized, hard, immovable, painless mass between his chin and his lower ear. It is closer to the chin, He said it can not be seen on the outside, but he can see it slightly on the inside of his mouth. He is looking for a doctor now. He has new insurance and is trying to get established. Any ideas as to what he is dealing with? Thank you for your help :-)