[Intraepidermal melanocytic proliferation. A practical guide to the classification of ambiguous melanotic skin lesions and of possible precursors of malignant melanomas].

A group of senior Pathologists engaged in review work on international randomized trials for the W.H.O and/or the E.O.R.T.C., propose a new simplified classification of melanocytic lesions with an intra-epidermal component, applicable in routine. This classification attempts to introduce standards to permit morphological identification of a large group of intra-epidermal melanocytic proliferations with three classes of atypia (slight, mild, severe) and group of malignant melanomas especially those without dermal invasion. The new definitions and objective criteria (at cytological and architectural level) of diagnosis are given with examples of equivalence between some established entities and this new universal terminology.