Proportionate growth of congenital nevi: Blow a balloon to explain.

Abstract

Any form of congenital nevus in a child is a cause of parental anxiety. Parents are often worried about the future course of the lesion. Some of these lesions grow in extent with the child's growth and involve other body areas; others grow proportionate to the involved body part, giving an impression of apparent growth of the lesion. We use an illustrative "blowing a balloon" technique to explain the apparent growth pattern of some congenital nevi