Two separate Consensus Development Conferences about the subjects of melanocytic nevi and melanoma were convened at the NIH in Bethesda, MD, the first from October 24–26, 1983 and the second from January 27–29, 1992. The aim of the conferences was to clarify knowledge then current about "precursors" of melanoma and about "early" lesions of melanoma. In both conferences, emphasis also was given to terminology, clinical and histopathologic aspects of benign and malignant neoplasms of melanocytes, and the biologic significance of "dysplastic nevi" (DN). Brief presentations about specific subjects were made to a Panel of respected representatives of different disciplines, in particular dermatology, pathology, oncology, genetics, epidemiology, internal medicine, and surgery, by well known workers in the field of melanocytic neoplasia, among them Ackerman, Clark, Elder, Fitzpatrick, Greene, Kopf, Kraemer, Lynch, Mackie, Mihm, Piepkorn, Rigel, Sagebiel, Sober, and Tucker.

The Consensus Development Conferences are structured in a manner designed to enable a Panel to assess critically observations and concepts provided to it by invited speaker-scientists prior to formulation of written answers by members of the Panel to prearranged "key questions" regarding issues considered to be controversial, riveting, and unresolved. The final written statements by the Panel of 1983 were published in mid-1984 in a number of journals, among them the Journal of the American Medical Association,¹ the Journal of the American Academy of Dermatology,² and the American Journal of Dermatopathology,³ whereas those by the Panel of 1992 appeared in the Journal of the American Medical Association in September 19924 and in the American Journal of Dermatopathology in January, 1993.5 The conclusions drawn by both Panels prompted animated discussion.^6–10

In order for readers to compare and contrast the positions taken by the Panels of the NIH Consensus Development Conferences of 1983 and 1992, statements about the same subjects will be quoted verbatim, followed by critical comment about them by us (Figs 1–4).