Natural history of melanocytic nevi.

The natural history of common acquired nevi begins with junctional nevi, which first evolve into compound nevi and then intradermal nevi. The clinical appearance and histopathology of these lesions permit precise identification. Spitz nevi, blue nevi, congenital nevi and dysplastic nevi represent subcategories that also have easily identifiable features. An understanding of the nature of benign nevi makes it easier to identify potentially life-threatening melanomas.