I've noticed a lump at the back base of my skull on the left side. It's hard, extends from a little ways behind my L ear to the middle of my skull and bulges out like a big goose egg. I've had chronic ear problems, feel dizzy and light headed and also have quite a lot of head and neck pain and pain in the area of the "bulge". I saw a Dr. of Otology and Neurotology who said I need surgery on my ear due to a retracted ear drum and mastoid problems. Would the lump at the back of my skull also be a mastoid issue that will be taken care of when he does the ear surgery, or could it be something else? Thanks.