Dysplastic moles
What is a dysplastic mole?
Dysplastic moles are benign growths of melanocytes. When looking at the cellular structure of a mole under the microscope, the pathologist has seen that there is abnormal development (dysplasia) of its cells. Depending on the extent of the abnormal development, they will grade the dysplasia as either ‘low grade’ or ‘high grade’.
Do dysplastic moles turn into melanoma?
There is no definitive answer at this time as research into dysplastic moles is ongoing. At one time it was proposed that there is a step-wise model of tumour progression from dysplastic moles through mild to moderate, then severe dysplasia, and finally melanoma in situ.
At this time, although there is no evidence that dysplastic moles are ‘common’ precursors of melanoma, it cannot be definitely ruled out.
There is a small sub-group of high grade dysplastic moles that, when seen in association with melanomas, show similar genetic mutations as melanomas do in their evolution. This suggests that some high grade dysplastic moles are an intermediate between benign moles and melanoma, and they should be completely excised.
When is it likely that a wider excision is needed?
Your doctor will take into account your personal medical history, their clinical judgement and the pathology report. They may decide that monitoring the site is the best way forward, or that a wider re-excision of the area around the lesion is necessary.
Does having dysplastic moles mean a greater chance of developing melanoma?
Current thinking is that most dysplastic moles do not progress to melanoma. However, it has been suggested that dysplastic moles are a marker for increased risk of melanoma at another site. Therefore it is important to regularly attend your doctor for a routine skin check, as well as informing your doctor about any changing lesions. References: Dysplastic naevi Patient fact sheet
Meridio 315494 August 2019 Sullivan and Nicolaides Pathology
