Image analysis cytometry of dysplastic nevi.

Computerized image analysis was used to assess nuclear atypia in 24 dysplastic nevi (DN), 19 CN (CN), and five thin melanomas. DN were selected for the study using architectural criteria alone. Feulgen-stained, 6-um sections were analyzed with a microTICAS cytometer. At least 100 nuclei were measured in each case. The standard deviation of nuclear area, mean nuclear roundness, standard deviation of nuclear roundness, mean ploidy, and standard deviation of ploidy were found to be significantly greater for DN than for CN. DNA histograms from DN showed an increased fraction above 2N, suggesting that DN are more proliferative than CN. No DN were aneuploid. All melanomas were aneuploid, and differed significantly from DN in mean nuclear area, standard deviation of nuclear area, mean ploidy, and standard deviation of ploidy. There were no significant differences between the junctional and intradermal populations of compound DN in any of the measured parameters, except that the intradermal nuclei were significantly rounder than the junctional nuclei. There were no significant differences between DN from patients with only a single DN and DN from patients with at least two dysplastic nevi.