CENTRALIA, Wash. (AP) -- Police are investigating how a 13-year-old Washington state boy got a tattoo.

The Centralia boy's mother and police tell KING-TV the 6-inch dragon tattoo was inked while the boy was on a trip with a family friend.

The boy, who wasn't identified, told his mom the tattoo marked his surviving leukemia. He isn't saying who did it.

It's a misdemeanor to tattoo a minor in Washington.