The dictionary defines dysplastic as an “abnormal growth or development of cells, tissue, bone, or organ” and nevus as “any congenital anomaly of the skin, including moles and various types of birthmarks,” or “any congenital growth or pigmented blemish on the skin; birthmark or mole.” So what is dysplastic nevus?
In 1978, the first report on what was named dysplastic nevus was published in the Arch Derm by Wallace Clark and colleagues. The neoplasm was defined as a unique type of melanocytic nevus that occurred in two families with melanoma and multiple such nevi. Because the histological and clinical findings in these patients were different from banal nevi, it was called “dysplastic nevus (DN),” implying with unusual, atypical (or dysplastic) features.
Questions that will be discussed are: what are the defining characteristics of dysplastic nevus? Are they clinical or histological? Are they reliable? Are they valid? What if the clinical features of a nevus are dysplastic but the histological findings are not? What should the name be? Should all clinically atypical-appearing nevi be biopsied? How should an incompletely excised DN be followed?