I have a what feels like a large mole on the back top corner of my head, it has been there for awhile, I have lots of moles so I thought it was just another big mole, I asked my roommate just to check and see if she could see the mole because I have been touching it alot lately because it seems bigger, she said its not a mole, I can't see it personally but could it be a syst of some sort?