During the course of a full skin examination, a 57-year-old white woman with a history of dysplastic nevus syndrome and basal cell carcinoma was found to have a distinct pigmented lesion on her chest.
The lesion, which occurred on a background of sun damage and lentigines, was noted to be asymmetric, possess irregular borders, demonstrate multiple colors, and extend well over 6 mm in greatest diameter (ABCD sign). The lesion was unlike any other on the patient’s skin surface (ugly duckling sign).