define dysplastic nevus
dysÂ·plasÂ·tic neÂ·vus. a nevus exceeding 5 mm in diameter, with irregular, indistinct, or notched borders and mixed tan-to-black and pink-to-red color. Microscopically these are basally nested and scattered intraepidermal melanocytes with hyperchromatic nuclei larger than those of basal keratinocytes.