Atypical/dysplastic nevi

Atypical nevi, also referred as dysplastic nevi, are characterized by intermediate aspects in between to common nevi and melanomas. From a clinical point of view, they usually show up as larger and more irregular and nonhomogenously pigmented lesions than common nevi. In dermatopathology, they are classically characterized by lentiginous melanocytic hyperplasia, epithelioid melanocytic atypia, lamellar fibroplasias and perivascular lymphocytic infiltrate [1]. From these observations a pathogenetic model for stepwise development of a MM from a nevus has been proposed. However, this model remains controversial due to nonclear and reproducible clinical definition of dysplastic nevus, limitations in recognition of early melanoma and dysplastic nevus, and weak correlation between histologic dysplasia and clinical atypia [2].