Histopathologic characteristics of dysplastic nevi. Limited association of conventional histologic criteria with melanoma risk group.

Studies of dysplastic melanocytic nevi (DMN) have suggested that lesions from patients with a personal or family history of malignant melanoma are histologically more atypical than are those from control populations without such histories. To evaluate this possibility, we examined histologic sections of DMN that had been removed from patients in three groups. Group A consisted of 17 subjects with a past history of melanoma; group B comprised 79 subjects with DMN and a family history of melanoma in first-degree relatives; group C consisted of 64 subjects who were unrelated spouses of members of groups A and B. For each group, sections of DMN were initially selected on the basis of architectural atypia as defined by the National Institutes of Health Consensus Conference. All biopsy material was then further evaluated for four histologic features suggested to be discriminatory for DMN associated with increased melanoma risk; the features are degree of junctional activity, irregularity of melanocytic nests, presence of dusty melanin, and size of melanocytic nuclei. A subjective rating was given for each on a 0 to 3 scale of increasing severity. Three pathologists individually rated the specimens without knowledge of the patient group. The means of the individual observer cumulative scores of the four histologic criteria for each biopsy specimen and the average of these means from the three observers exhibited a trend to increasing values from groups C to A, but none of the differences reached statistical significance.(ABSTRACT TRUNCATED AT 250 WORDS)