Nuclear and cytoplasmic features in the diagnosis of banal nevi, Spitz nevi, and melanoma.

BACKGROUND

Many authors have described cytologic features in a variety of melanocytic lesions but, to our knowledge, a statistical analysis of sensitivity, specificity, and overall accuracy of these features alone or in combination has not been performed.

OBJECTIVE

We sought to determine the diagnostic value of nuclear and cytoplasmic characteristics in the diagnosis of melanocytic lesions via multivariate statistical analysis.

METHODS

This is a retrospective observational study conducted on 300 melanocytic lesions. We evaluated a series of distinctive features; subsequently a multivariate model was used to determine sensitivity and specificity.

RESULTS

Major features that favor a diagnosis of melanoma include: pleomorphism with enlarged nuclei, mitotic figures, notching/corrugation of the nuclear envelope, and peppered moth nucleus. Features with intermediate value include: solid hyperchromasia, vesicular nucleus with single round nucleolus, and nuclear/cytoplasmic ratio greater than 4:1.

LIMITATIONS: Limitations of this study include its retrospective nature, and the reliance on the original diagnostic classification of each neoplasm.

CONCLUSION

Our data suggest that some nuclear alterations have greater value in the diagnosis of benign and malignant melanocytic lesions.