My hamster has a small spot and i think it's growing?HELP URGENT.?

He has a small pink spot on his "eyebrow" bit. And im worried in-case it grows! it looks like a human spot and is not soft, but hard. He is acting really well, eating, drinking, wakening me up at night with his wheel etc. But i dunno what to do with this spot?! Anything i can do to stop it growing? I really need help asap.