I have a bump on anus right near the hole. looks gray. feels like part of the skin but appeared 3 days ago. hurts a little. itchy. 17 y/o male.cancer?

Skin tag, hemorrhoid: It could be many things-- skin tag, external hemorrhoids, perianal abscess etc. The risk for you to have anal cancer- at your age- is low. See your md and have it examined, if it bothers you.

More likely : Hemorrhoid. It is more likely to be external hemorrhoid/pile. It would be prudent to get it checked out and treated.

Probably not: Cancer this are on a 17 year old would be very rare. Have you been straining or been constipated lately? You should bring this symptom to the attention of your friendly primary care physician.