MORPHOMETRIC ANALYSIS OF MELANOCYTIC TUMORS - A STUDY OF NUCLEAR-AREAAND DENSITY

Because the differential diagnosis of melanocytic tumors is sometimes difficult, we performed a morphometric analysis of 20 benign nevi, 20 malignant melanomas, and 10 Spitz's nevi. The nuclear pleomorphism and the maturation to the depth of the tumor were quantified by measuring nuclear area and nuclear density at serial levels of the tumor (every 220 mu m of thickness). Data obtained were analyzed statistically. Li near regression was used to represent the variation of nuclear area to the depth, and the standard deviation of nuclear areas reflected nucl ear pleomorphism. We attempted to separate different tumors from each other using the Jacknife procedure and morphometric data. Using the Ja cknife procedure rather than the usual histological procedures, we wer e able to distinguish benign nevi from Spitz's nevi and malignant mela noma in as many as 92% of cases, but we distinguished Spitz's nevi fro m malignant melanoma in only up to 60% of cases. In conclusion, we fou nd it difficult to distinguish between Spitz nevi and melanoma using n uclear morphometric parameters. Other studies using new morphometic pa rameters are needed in order to improve our ability to make this discr imination.