Clinicopathologically Defined Nevus Subtypes and Melanoma Risk

Early detection of melanoma is a major determinant in disease outcome and drives the number of (over)excised nevi in clinical practice. This study aimed to evaluate demographic features and melanoma risk of clinically suspicious, mainly flat nevus subtypes. Based on the methodology of ex vivo dermoscopy and derm dotting, the 12 most prevalent nevus subtypes were identified in a collection of over 7000 nevi excised for medical reasons. Dermoscopical, histopathological and clinical features of these subtypes were described. In addition, the association with melanoma history, histopathological atypia and melanoma occurrence within nevi was compared. Nearly half of the nevi removed for medical reasons were of the hypermelanotic subtype with no or mild histopathological atypia and low melanoma association, suggesting overtreatment in daily practice. Contrarily, the subtypes atypical lentiginous nevus and orange pulverocytic flat nevus were associated with higher proportions of (severe) atypia and melanoma (history). We believe these subtypes may reflect different tumoral and/or (germline) genetic entities with different melanoma risk. The data from this study may direct further prospective research on specific nevus subtypes in order to obtain better insights in associated clinical/genetic factors and melanoma risk.