What is dysplastic nevus?

➢ Dysplastic nevi may be sporadic or familial. ➢ The latter are important clinically because they identify individuals who have an increased risk of developing melanoma. ➢ As with conventional melanocytic nevi, activating RAS or BRAF mutations are commonly found in dysplastic nevi and are believed to have a pathogenic role. ➢ larger than most acquired nevi (often more than 5 mm across) and may number in the hundreds. ➢ flat macules to slightly raised plaques, with a “pebbly” surface ➢ They usually have variable pigmentation (variegation) and irregular borders