An analysis of interobserver recognition of the histopathologic features of dysplastic nevi from a mixed group of nevomelanocytic lesions.

Abstract

The diagnostic criteria for the histopathologic recognition of the dysplastic nevus are defined, but difficult to apply in practice. However, the use of skin biopsy is on the increase to search for this nevus because of a possible role in melanomagenesis. The aim was to determine the degree of observer reproducibility in the detection of histologic nevomelanocytic dysplasia as measured across multiple observers and to test whether each observer was precise over a wide sample population. A second aim was to gain some measure of the threshold a person has for such lesions. Histologic specimens from 50 coded nevomelanocytic tumors, which included a group of dysplastic nevi, were independently read by five observers in a blinded fashion. At study completion, the same 50 cases were read again by a melanoma reference pathologist and results analyzed by Cohen's kappa to assess agreement and interobserver variation. Corrected rates of agreement for dysplastic nevi ranged from 0.32 to 0.71. Continued study and experience are required for precision and reproducibility in the histologic recognition of dysplastic nevi.