While the incidence of early-stage melanoma has dramatically increased over the past decades, the incidence and mortality rates of thick melanomas have remained relatively stable during the same period. A number of alternative theories have been postulated in order to explain these divergent trends between thin and thick melanomas, among which is the question of whether nodular melanoma may originate in the dermis. This concept has gained support from recent improvements in the understanding of the origin of melanocytes and the morphological and molecular diversity of melanoma. A dermal origin would plausibly explain why efforts at improving the early detection of melanoma largely fail, as it implies an initially intradermal growth that is hidden from our eyes until clinical signs and symptoms become only secondarily apparent. In light of this, at the current stage, the vision that no one should die of melanoma is an impossible mission.
Keywords: diagnosis; epidemiology; melanoma; melanomagenesis; screening.