Bruce P.Robinson, MD
Everyone has moles, sometimes 40 or more. Most people think of a mole as a dark brown spot, but moles have a wide range of appearance. At one time, a mole in a certain spot on the cheek of a woman was considered fashionable. These were called "beauty marks." Some were even painted on. However, not all moles are beautiful. They can be raised from the skin and very noticeable, they may contain dark hairs, or they may be dangerous.
Moles can appear anywhere on the skin. They are usually brown in color but can be skin colored and various sizes and shapes. The brown color is caused by melanocytes, special cells that produce the pigment melanin. Moles probably are determined before a person is born. Most appear during the first 20 years of life, although some may not appear until later. Sun exposure increases the number of moles, and they may darken. During the teen years and pregnancy, moles also get darker and larger and new ones may appear. Each mole has its own growth pattern. The typical life cycle of the common mole takes about 50 years. At first, moles are flat and tan like a freckle, or they can be pink, brown or black in color, Over time, they usually enlarge and some develop hairs. As the years pass, moles can change slowly, becoming more raised and lighter in color. Some will not change at all. Some moles will slowly disappear, seeming to fade away. Others will become raised far from the skin. They may develop a small "stalk" and eventually fall off or are rubbed off.
Recent studies have shown that certain types of moles have a higher-than-average risk of becoming cancerous. They may develop into a form of skin cancer known as malignant melanoma. Sunburns may increase the risk of melanoma. People with many more moles than average (greater than 100) are also more at risk for melanoma.
Moles are present at birth in about 1 in 100 people. They are called congenital nevi. These moles may be more likely to develop a melanoma than moles which appear after birth. Moles known as dysplastic nevi or atypical moles are larger than average (usually larger than a pencil eraser) and irregular in shape. They tend to have uneven color with dark brown centers and lighter, sometimes reddish, uneven border or black dots at edge. These moles often run in families. People with dysplastic nevi may have a greater chance of developing malignant melanoma and should be seen regularly by a dermatologist to check for any changes that might indicate skin cancer. Those susceptible should also learn to do regular self-examinations, looking for changes in the color, size or shape of their moles or the appearance of new moles. Sunscreen and protective clothing should be used to shield moles from sun exposure. Recognizing the early warning signs of malignant melanoma is important. Remember the ABCDs of melanoma when examining your moles: Read more here for Dr. Robinson in the News on Moles.
