Pathologists tend to reclassify prior nonmalignant diagnoses

(HealthDay) -- For dermatopathologists there is a trend toward reclassification of prior nonmalignant diagnoses of severely atypical dysplastic nevi as malignant, according to a study published in the September issue of the Journal of the American Academy of Dermatology.

Jason E. Frangos, M.D., from Harvard Medical School in Boston, and colleagues had a group of nine dermatopathologists review retrieved pathology files and reevaluate 29 cases of dysplastic nevi with severe atypia and 11 cases of thin radial growth-phase melanoma, originally diagnosed in 1988 through 1990.

The researchers found the mean number of melanoma diagnoses in the revaluation to be 18, an increase from the 11 original diagnoses of melanoma. In all 11 cases, a majority agreed with the original melanoma diagnosis. In four of the 29 cases originally reported as dysplastic nevus with severe atypia, a majority of current raters diagnosed melanoma. Interrater agreement over time was excellent for cases originally diagnosed as melanoma (kappa, 0.88), and fair for cases originally diagnosed as severely atypical dysplastic nevus (kappa, 0.47).

"The results of this study provide support for the hypothesis that dermatopathologists are more likely to diagnose thin superficial spreading melanoma in biopsy specimens that were reported as dysplastic nevi with severe atypia in the past, e.g., some 20 years ago," the authors write.