NUCLEOLAR ORGANIZER REGIONS IN CONJUNCTIVAL NEVI AND MELANOMAS

The objective of this study was to compare the argyrophil nucleolar or ganizer region (Ag-NOR) counts of conjunctival nevi and melanomata and to compare the efficacy of this method in their differential diagnosi s. Nine histologically diagnosed conjunctival nevi and three conjuncti val malignant melanomas were studied. Representative sections were sta ined using the AgNOR technique. Fifty cells of each melanocytic lesion were randomly selected without knowing their histologic diagnosis. Th e AgNORs were visualized at a magnification of x1000. They consisted o f clusters >1 micron in diameter and of satellites <1 micron in diamet er, which were counted and recorded for each cell separately. The mean AgNOR count for the nevi was 1.12 clusters and 1.72 satellites per ce ll, while the count for the melanomas was 1.6 clusters and 6.8 satelli tes per cell. These results are statistically significant. There was n o overlap between the number of AgNOR clusters and satellites in conju nctival nevi and melanomas, indicating that the AgNOR count might be a useful tool in distinguishing benign from malignant conjunctival mela nocytic lesions.