Diagnosis and management of premalignant melanocytic proliferations.

The histopathology of melanocytic proliferations in human skin can be defined in a way which allows a rational approach to their management. Early and/or premalignant lesions such as melanocytic hypertrophy, hyperplasia, dysplasia, and atypical hyperplasias are correlated with clinical lesions such as lentigo, compound nevoid lentigo, changes in nevi during pregnancy, and unusual moles seen in patients with the dysplastic nevus syndrome. Clinical management of such lesions may be determined from the pathological process. Hypertrophic and hyperplastic lesions need not be re-excised, although partially removed moles showing junctional hyperplasia may recur clinically. The mildly and moderately dysplastic nevus need only be narrowly removed. Severe dysplasia and melanoma in situ may recur locally as invasive melanoma, and consideration for conservative reexcision is warranted. Dysplastic nevi should be considered to be markers of patients who may develop melanoma. Patients with dysplastic nevi or a family history of unusual moles or melanoma should have continued follow-up, preferably with standardized clinical photographs.