Don't fret. My DD had exactly the same thing, behind her ear. I took her to doctors and MCHNs etc.. They said that it was cartilage/bone that the body hadn't absorbed and that it would disappear. I was always checking on it and then one day it disappeared. She was probably about 12-18months old. I thought she had cancer and conjured up allsorts of illnesses which she could possibly have.

My best bet would be to take her to the dr and just have it on her file, incase it doesn't go away, but i am sure it will.

Don't fret

xxoo