Why Do I Have Lumps On Head?

Hi I'm a 24 male who is wondering what these mulitply lumps on top of my head which creates ridges. They are from 3 to 5 inches long and feel hardened in some spots, soft in other spots. They pretty much look like a package of hot dogs on top of my head. Which I've had them since long I can remember around 8 yrs old or so. My question is what can cause this? and can they be removed by a neurosurgeon? Cause my self esteem has dropped alot from these condition.