Dysplastic nevi are moles that are generally larger than average (larger than a pencil eraser) and irregular in shape. They tend to have uneven color with dark brown centers and lighter, uneven edges. These nevi are somewhat more likely to become melanoma. In fact, people who have 10 or more dysplastic nevi have a 12 times higher chance of developing melanoma, a serious form of skin cancer. Any changes in a mole should be checked by a dermatologist to evaluate for skin cancer.