[Quantitative analysis of nucleolar organizer regions in nevi and melanomas]

The results of a quantitative analysis of nucleolar organizer regions (NORs) in a group of 45 nevi and 45 melanoma are presented. Mean value of nucleolar organizer regions in nevi was 1.29 and the standard error 0.088. Melanoma had mean value of 3.90 with a standard error of 1.542. Student's t test revealed a statistically significant difference between these two groups of benign and malignant melanocytic lesions of skin (P < 0.001), with regard to the number of NORs. In view of these results and those from the literature, the diagnostic value of the number of NORs in distinguishing benign from malignant melanocytic lesions of skin has been confirmed.