Moles (nevi) are a skin growth formed by a cluster of melanocytes, the cells responsible for the production and storage of melanin (pigment). They usually appear as small brown spots but can vary in size and color. They are quite common, are usually harmless, and very rarely become cancerous. Most moles appear in childhood and adolescence, and by the time a person reaches fifty years of age, they will likely have between ten and forty moles on their body. They can change appearance over time and hormonal changes during puberty or pregnancy can often cause them to become larger or darker in color.

Keeping an eye on any changes in existing moles is important in detecting potential skin cancer. A helpful tool for performing self- examinations is called the ABCDE guide. As moles can appear anywhere on the entire body, even under the hair or fingernails, one should do a full head-to-toe check once a month. “A” stands for asymmetrical shape, so look for differences between one half of the mole and the other. “B” is for borders. Are the edges of the mole, scalloped or irregular? “C” stands for color. Any changes in color- darkening, unevenness, or multiple colors in the same mole should be noted. “D” if for diameter. Moles typically should be less than one quarter of an inch in diameter, so be on the lookout for any growth, but especially growth that exceeds that size. Finally, “E” is for evolving. Make sure your dermatologist is aware of any changes in size, shape, height, or color, or if the mole becomes itchy or begins to bleed.

Moles typically do not need any treatment or special care. However, getting a professional skin examination every six months to a year is recommended, especially if any of the following risk factors exist: being born with large moles over two inches in diameter, having unusual moles that are irregular in shape of size, having a large number (over 50) of moles on the body, or having a family history of melanoma (skin cancer).