A seborrheic keratosis (seb-o-REE-ik ker-uh-TOE-sis) is a common noncancerous (benign) skin growth. People tend to get more of them as they get older. Seborrheic keratoses are usually brown, black or light tan. The growths (lesions) look waxy or scaly and slightly raised. They appear gradually, usually on the face, neck, chest or back.