I could make a "plane" joke here but I won't. If it's not cancerous then at least aesthetically speaking it's very distracting. Maybe his skull is malformed and his brain extends into the lump, that's the only reason I wouldn't have it removed.
I know, I know, MYOB. I guess I won't watch the show until he removes it.
I watched a local news show where a man had a cancerous reddish growth on top of his skull about the same size, and he was geting chemotherapy.
I wish him well though, I'm not trying to make fun of him.