Study to Test Genetic Alterations Among Different Dermoscopic Types of Melanocytic Nevi.

BRAF and Nevi.Nevi Are Common Benign Pigmented Tumors of the Skin. Mutations in So-called BRAF and NRAS Genes Genes Appear to be Initiating Events Responsible for the Formation of Nevi.

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

Benign nevi dermoscopically sub-classified into 4 dermoscopic types (i.e., with globular, reticular, mixed pattern with globules in the center and mixed pattern with globules at the periphery) were excised from healthy volunteers for further genetical analysis

Benign nevi excised for the study purpose where genetically analyzed for the presence/absence of BRAF and NRAS mutations

All nevi were analyzed for BRAF mutations using the (less sensitive) Sanger method. A random subset of nevi was also analyzed using the (more sensitive) Ultradeep pyro-sequencing method (UDPS). The frequency is reported here as the number of BRAF mutations found by each method.

All nevi were analyzed for NRAS mutations using the (less sensitive) Sanger method. The (more sensitive) Ultradeep pyro-sequencing method (UDPS) is not applicable for this mutation. The frequency is reported here as the number of NRAS mutations from the analyzed nevi.

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

Zalaudek I, Grinschgl S, Argenziano G, Marghoob AA, Blum A, Richtig E, Wolf IH, Fink-Puches R, Kerl H, Soyer HP, Hofmann-Wellenhof R. Age-related prevalence of dermoscopy patterns in acquired melanocytic naevi. Br J Dermatol. 2006 Feb;154(2):299-304. doi: 10.1111/j.1365-2133.2005.06973.x.

Zalaudek I, Hofmann-Wellenhof R, Soyer HP, Ferrara G, Argenziano G. Naevogenesis: new thoughts based on dermoscopy. Br J Dermatol. 2006 Apr;154(4):793-4. doi: 10.1111/j.1365-2133.2006.07152.x. No abstract available.

Pellacani G, Scope A, Ferrari B, Pupelli G, Bassoli S, Longo C, Cesinaro AM, Argenziano G, Hofmann-Wellenhof R, Malvehy J, Marghoob AA, Puig S, Seidenari S, Soyer HP, Zalaudek I. New insights into nevogenesis: in vivo characterization and follow-up of melanocytic nevi by reflectance confocal microscopy. J Am Acad Dermatol. 2009 Dec;61(6):1001-13. doi: 10.1016/j.jaad.2009.04.018. Epub 2009 Oct 14.