The epidermal and dermal origin of melanocytic tumors: theoretical considerations based on epidemiologic, clinical, and histopathologic findings

A better understanding of the origin and evolution of nevi may help elucidate the pathways involved in melanoma-genesis. Herein we will present our theory of 2 distinct pathways to nevogenesis. We postulate, based on clinical observations and research data, that junctional nevi and superficial spreading melanomas arise from epidermal melanocytes, whereas dermal nevi and nodular melanomas originate in the dermis.