swollen gland under right chin, pics

hey all, so i recently went to a specalist, and she recommanded me surgery to remove it... but even she doesnt know for sure what it is, except that its not supposed to be there, i got ultrasound, MRI, both done, and they cant tell me what it is, basically all results were inconclusive

i think ive had this since last year, maybe its been there for 1 year and a half?
its soft, and not painful, i dont have any fevers/chills/night sweats etc, or is there any pains in that area. it has not grown, its size its around the same, sometimes a bit smaller, sometimes a bit larger.. i BELIEVE, this started when i got a sore throat/cold/fever 1yr and a half ago, and has been swollen ever since... (and i also got my wisdom tooth, on my right side 2 yrs ago, could this have affected it too?)

does anyone know what it could be?

http://imageshack.us/photo/my-images/831/123jic.png/
http://imageshack.us/photo/my-images/831/1234ar.png/