This project is a multicenter study in which we will investigate a dual concept of nevogenesis. Study location is the Department of Dermatology at the Medical University of Graz in collaboration with centers in Austria (Vienna), Italy (Naples, Benevento, Modena), Spain (Barcelona) and the United States (New York).

The hypothesis is that small congenital melanocytic nevi (CMN), "early" acquired melanocytic nevi in childhood (AMN) and dermal nevi, all dermatoscopically characterized by globular pattern, belong to the same spectrum of genetically determined melanocytic proliferations that develop due to endogenous pathways, in contrast to "true" acquired melanocytic nevi, dermatoscopically showing reticular pattern, that develop due to exogeneous factors such as UV-exposure.

The investigations to this study will verify whether small CMN, "early" AMN and dermal nevi, characterized by globular pattern differ in their genetic alterations compared to reticular typed nevi. It will be expected that globular typed nevi and eventually dermal nevi lack B-RAF mutations whereas reticular nevi show alterations in the B-RAF gene. Study location: Graz

Inclusion Criteria:

• Healthy individuals aged 9 to 80 years showing one or more dermoscopically benign nevi with either uniform globular-cobblestone pattern or reticular pattern or a combination of both types

Exclusion Criteria:

• Children under the age of 9 years
• Pregnant woman
• Patients with atypical nevi (i.e., melanoma cannot be clinically ruled out)
• Patients with immunosuppression
• Patients with sun exposure 4 weeks before enrollment

were not collected or assessed

postoperative complications were not collected or assessed

During first year of enrollment too few patients agreed to participate. Therefore a sample of 21 nevi were additionally retrospectively included.