References

1. Elder DE, Goldman LI, Goldman SC, Greene MH, Clark WH Jr: The dysplastic nevus syndrome: a phenotypic association of sporadic cutaneous melanoma. Cancer 1980; 46: 1787-1794.
2. Clark WH Jr, Elder DE, Guerry D IV, Epstein MN, Greene MH, Van Horn M: A study of tumor progression: the precursor lesions of superficial spreading and nodular melanoma. Hum Pathol 1984; 15: 1147-1165.
3. Ackerman AB: What nevus is dysplastic, a syndrome and the most common precursor of malignant melanoma? A riddle and an answer. Histopathology 1988; 13: 241-256.
4. Piepkorn M: A hypothesis incorporating the histological characteristics of dysplastic nevi into the normal biological development of melanocytic nevi. Arch Dermatol 1990; 126: 514-518.
5. Klein LJ, Barr RJ: Histologic atypia in clinically benign nevi. A prospective study. J Am Acad Dermatol 1990; 22: 275-282.
6. Urso C, Bondi R: The histologic spectrum of acquired nevi. An analysis of the intraepidermal melanocytic proliferation in common and dysplastic nevi. Path Res Pract 1994; 190: 609-614.
7. Urso C. Atypical histological features in melanocytic nevi. Am J Dermatopathol 2000; 22: 391-396.

The concept of "dysplastic nevus" has been proposed at the end of the 70's, as a particular nevus, identifiable clinically and histologically, playing the role of melanoma precursor and of risk marker [1]. Such a concept exploded in the scene of melanocytic lesions pathology, raising a large and hard controversy on several aspects of the problem. Although strongly contrasted, the concept of dysplastic nevus began to be accepted and used by many clinicians and pathologists. Examining the specific literature, however, it appears that authors, although they refer to the same concept, have deeply different opinions about primary aspects of the lesion (clinical and histological features, the precursor role, risk marker role)[2,3,4]. Particularly, at the beginning of 90's, it emerged that in dysplastic nevi clinical features do not constantly correspond to histological ones, showing that the lesion, as defined, can be hardly considered a true clinicopathological entity [5]. It also emerged that the histological border between dysplastic nevus and common nevus is not well defined, because many nevi showing intermediate characteristics do exist; under this light, it also appears hard that dysplastic nevus can be considered a real distinct histologic entity [6]. In fact, if nevi are investigated for the histological features considered to be specific of dysplastic nevi, rather than two distinct classes of lesions, they form a contiunuous spectrum of lesions showing an increasing incidence of atypical festures [7]. These results invite to reflect and seem to indicate, on one hand, that the concept of dysplastic nevus, as defined, cannot be used, and, in the other hand, that a new different approach to the nevi diagnosis is opportune.

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