Dysplastic melanocytic nevus: Are molecular findings the key to the diagnosis?

The primary differential diagnosis of melanoma is dysplastic nevus. Until now, the final diagnosis is based on histological findings. With modern techniques, pathologists receive very early melanocytic lesions, which do not fit all malignant criteria. In those cases, even the concurrence between specialists and intraobserver agreement is not good. A molecular test could be developed to improve the accuracy of melanocytic lesions diagnosis and help in challenging lesions. The objective of this study is to provide a literary review looking for molecular markers that characterize dysplastic nevi and could help surgical pathologists differentiate them from melanoma. Articles from PubMed presenting case series of dysplastic nevi and melanoma genomic analyses were considered. The search was conducted in PubMed looking for papers written in English, published in the ten years preceding April 2020. This review confirmed the absence of a pathognomonic molecular marker of dysplastic nevi. This is a heterogeneous group of lesions with an uncertain risk to become a melanoma. The molecular heterogeneity of dysplastic nevi, the variation of histological diagnostic criteria among services, and the diverse molecular techniques applied are challenging features that might hamper definitive diagnoses. However, currently, there appears to be limited value for molecular testing in the diagnosis of dysplastic nevi.