In the late 1940's, Arthur Allen spawned the notions of junctional activity and active junctional nevi, concepts that soon became incorporated into the mind-set and parlance of general pathologists worldwide. Within 25 years, those concepts were completely discredited and abandoned. Why? Because Allen's premises were dead wrong, namely, that melanocytes spring from keratinocytes, that "activity" can be recognized through a microscope, and that all melanomas derive from pre-existing "restive" melanocytic nevi. Even cursory inspection of the many photomicrographs published by Allen captioned "active junction nevus" reveals every one of them to be a stereotypical melanoma in situ.

In the late 1970's, Clark launched the notions of melanocytic dysplasia, DN, and DNS. The foundations on which those concepts were constructed were as rickety as those of Allen. After 20 years, Clark, co-workers, and acolytes, in hundreds of articles, have yet to issue repeatable comprehensive definitions of and criteria for melanocytic dysplasia, DN, and DNS. Despite this, scientists in different corners of the globe are in hot pursuit of a gene supposed to be responsible for the DN-melanoma syndrome. Clinicians worldwide continue to do injury to patients by frightening them, unnecessarily, about risk of melanoma based on the presence of a single DN and by removing, unnecessarily, obvious nevi, sometimes many of them, all of which prove by microscopy to be benign.

Clark, who has created a "small industry" (more than 50 articles published in 16 years about the wooly notions of what he calls melanocytic dysplasia, DN, and DNS), decries the controversies that have resulted from that industry (British Medical Bulletin, 1995). We decry the fact that there has not been more controversy about those ideas, dissatisfaction that prompted us to review those subjects critically in the four part series that has appeared in this journal. Not surprisingly, considering the woeful state of medical "education," it is just as difficult to find in the literature of pathology a dissenting opinion to that of Clark about DN as it was of Allen about "active junction nevus." The end of DN will be the same as that of active junction nevus, and that demise is inevitable, independent of our comments about it. If, however, our efforts have contributed to hastening the end of the myth of DN and the DNS, we take some measure of satisfaction from having spared some patients unnecessary physical and emotional injury.

Our purpose, beyond that of an intellectual exercise conducted in critical, incisive, and academic fashion, is to encourage colleagues in pathology and in dermatology to participate, in a socially conscionable way, in debate about issues of the day. It is unlikely that those who shrink from resisting "dysplasia" will be more courageous about opposing demagoguery, despotism, and demons of all kinds.