Also know as atypical moles are unusual benign moles that may resemble melanoma. People who have them are at increased risk of developing single or multiple melanomas. The higher the number of these moles someone has, the higher the risk; those who have 10 or more have 12 times the risk of developing melanoma compared to the general population. Dysplastic nevi are found significantly more often in melanoma patients than in the general population.

Medical reports indicate that about 2 to 8 percent of the Caucasian population have these moles. Heredity appears to play a part in their formation. Those who have dysplastic nevi plus a family history of melanoma (two or more close blood relatives with the disease) have an extremely high risk of developing melanoma. Individuals who have dysplastic nevi, but no family history of melanoma, still face a 7 to 27 times higher risk of developing melanoma compared to the general population—certainly a great enough risk to warrant monthly self-examination, regular professional skin exams and daily sun protection.

People with dysplastic nevi and a family history of dysplastic nevi and melanoma tend to develop the cancer at an earlier age than melanoma patients who don’t have such nevi. Individuals who have dysplastic nevi but no family history of dysplastic nevi and melanoma may also develop melanoma at a relatively early age, but less often.

At times it is difficult to distinguish between dysplastic nevi and early melanomas. (Sometimes, melanomas will begin within a dysplastic nevus.) To establish the difference, a doctor will remove the entire spot or a portion of it for examination in the pathology laboratory. Some physicians recommend examining the mole with a dermoscope, which magnifies and allows visualization of internal structures and colors not seen by the naked eye.