Differentiation of atypical moles (dysplastic nevi) from early melanomas by dermoscopy

Several dermoscopic features have been identified as characteristic for melanoma; however, the reliability of these criteria in differentiating early melanomas from atypical moles has yet to be determined. The authors found the following dermoscopic features to be useful (i.e., highly specific) in differentiating early melanoma from atypical moles: a pigment network that ends abruptly; the presence of white scar-like areas; depigmented areas; and whitish veil. Although pseudopods, brown globules, and black dots of variable size were also specific for melanoma, they were infrequently seen with early melanomas to be beneficial in distinguishing them from atypical moles. Newly identified dermoscopic features that were found to be helpful in differentiating atypical moles from early melanoma included: the presence of red, blue, gray, or white color; the presence of four or more colors; moderate to marked border irregularity, and the presence of multiple, variably sized homogeneous areas. The presence of any combination of these specific features should elevate the index of suspicion for melanoma and should prompt a biopsy to avoid missing this cancer.