Dysplastic Naevi

A naevus is a benign growth occurring on the skin, better known as a ‘mole’. There are several different types of moles, classified based on their appearance, site, age of development and whether or not they are atypical. A dysplastic naevus is a mole with atypical or unusual features when viewed under the microscopic. Depending on the degree of ‘dysplasia’, they can be labelled as either low or high grade according to the classification system introduced by the World Health Organisation in 2018.

There is considerable controversy surrounding the behaviour of dysplastic naevi and their potential to develop into melanoma. Current thinking is that they do not progress to melanoma, however they are considered to be a marker for increased risk at other sites. Based on the similarity in genetic mutations between high grade dysplastic naevi and melanoma in evolution, as a precaution, complete excision of this grade of lesion is recommended. Overall, when deciding how to treat dysplastic naevi, your dermatologist will take into account their clinical suspicion, degree of dysplasia under the microscope, your personal and family history of melanoma.