Hey there, I'm 15 years old and just noticed a lump on the back of my head. I looked up what it possibly could be and I honestly thought to myself "brain tumor" or "cancer"! Anyways I looked up the structure of the skull and defination of ever single piece of the skull. I found "external occipital protuberance" and it seems as if everyone has this. It hard, it doesn't hurt or itch, it's under the skin. And it's small maybe grape size. Please help!