Melanoma accounts for the majority of deaths resulting from skin cancer. It is an aggressive malignancy of the pigment-producing melanocytes. The “ugly duckling” sign characterizes a lesion that appears to be an outlier in the presence of similar-appearing moles. The ABCDE rule is a guide to identify the typical signs of melanoma: A) asymmetry in shape – one half unlike the other B) border irregularity C) color variability – shades of brown, black, gray, red, and white D) diameter greater than 6 mm E) evolving – the lesion is changing in size, shape, or shade of color Source
