“…On the homepage patients or their parents are requested to fill out an electronic questionnaire with data of CMN with a diameter of 3 cm or more in newborns or 10 cm in adults being registered. The aim of this registry is to gain insight on frequency of CMN, their risk of malignancy and their clinical course (http://www.naevus-netzwerk.de) [Krengel S et al 2008].…”