Melanoma tumors resemble moles on the skin or may develop from a pre-existing mole, according to the Skin Cancer Foundation. Melanoma tumors are usually black or brown and differ from moles in five ways, which are known as the ABCDEs of melanoma.
The A represents that melanoma tumors are asymmetrical. Benign moles are typically symmetrical. B stands for border, as the borders of melanoma are uneven, scalloped or notched, while those of benign moles are smooth and clearly defined. The C explains that melanoma can take multiple colors, which often include different shades of brown, black and tan and sometimes even red, white or blue. Normal moles are usually a single shade of brown, the Skin Cancer Foundation advises.
The letter D represents diameter, as melanomas are large, usually greater than 6 millimeters in diameter, but can be smaller depending on how early they are detected. The E represents a mole evolving or looking different than it previously did, which suggests the development of a benign mole into a cancerous one, explains the Skin Cancer Foundation.
Any skin imperfection that matches one or more of these characteristics may be cancerous and should be checked out. Early action is very important, according to the Skin Cancer Foundation, as melanoma is easily treatable in its early stages but has a high fatality rate if it spreads and metastasizes.