Features that suggest melanoma, known as the ABCDEs of melanoma, are A: Asymmetry—asymmetric appearance B: Borders—irregular borders (ie, not round or oval) C: Color—color variation within the mole, unusual colors, or a color significantly different or darker than the patient's other moles D: Diameter— > 6 mm E: Evolution—a new mole in a patient > 30 years of age or a changing mole Although clinical findings can sometimes establish a diagnosis of atypical moles (see table Characteristics of Atypical vs Typical Moles), visual differentiation between atypical nevi and melanoma can be difficult; biopsy of the worst-appearing lesions should be done to establish the diagnosis and to determine the degree of atypia.