The ABCDs of moles and melanomasByRobert J. Friedman, MD,Darrell S. Rigel, MD,Alfred W. Kopf, MDJuly 1st 2007When you inspect moles, pay special attention to their sizes, shapes, edges, and color. A handy way to remember these features is to think of the A, B, C, and D of skin cancer-asymmetry, border, color, and diameter.