I've had the same thing and just got back the doctor. Specifically what I had was a bump at the very back of my jawbone next to my ear lobe. I first noticed it about 6 years ago. It felt like a button or an m&m under the skin. It was hard and painless and frankly, pretty easy to ignore except for the fact that it was there. A year or so later I went to the doctor for something else and mentioned the lump. He felt it and said not to worry about it. Fast forward 6 years and over time it's gotten a little bigger. It's now about the size of a lifesaver and if I look at myself in a mirror I can notice a slight bump compared to the other side. Last week I went to my regular doctor for something else and mentioned the bump again. Again I was told it was probably nothing, but I was given the option of getting a referral to an ear, nose & throat doctor (otolaryngologist) if I wanted. Even though it doesn't hurt, and has never hurt, there's a bit of stress involved in something being there that isn't supposed to be there.

I went to the ear, nose & throat doctor this morning and he said what I have is a "parotid mass". Basically it's a tumor in the parotid gland (large salivary gland). He said these are "very rarely cancerous". (whew!) It is suggested that it be removed because if left untouched over time it can grow and eventually affect the facial nerve or could possibly convert to cancer so it's best gotten rid of, though you do have to weigh the risks of that with the risks of surgery would could also cause some facial nerve damage. Probably the best thing to do would be to see an otolaryngologist and let them take a look. If it's nothing, or it's something but it's not worth touching right now (my understanding is they might opt not to do anything about lump under 1cm or something) then he or she will say so. And if it's something then this is definitely a case of "an ounce of prevention is worth a pound of cure". The good news is, it isn't necessarily bad, and wouldn't you like not to worry about it anymore?

Best of luck!