What is a dysplastic (atypical) melanocytic nevus?

Dysplastic or atypical nevus is a controversial term that has eluded a precise definition. It has been commonly used to describe an atypical-appearing melanocytic nevus believed to have increased potential for malignant transformation. Since this lesion was first described, the atypical nevus has been the subject of controversy. Argument has centered on the criteria for its histopathologic diagnosis, the incidence of melanomas developing in the lesion, and the histopathologic association of melanoma arising in an atypical nevus.

Naeyaert JM, Brochez L: Clinical practice. Dysplastic nevi. N Engl J Med 349:2233–2240, 2003