Each year, more than 1 million cases of skin cancer are diagnosed in the United States, and one person dies every hour from melanoma or nonmelanoma skin cancer. According to the American Cancer Society about 44,200 new cases of melanoma and 7,300 deaths are reported each year. Melanoma is a form of skin cancer that arises in melanocytes - the cells that produce melanin pigment found in the skin. Melanoma is a serious type of skin cancer, because it can spread to other parts of the body. A nevus is a benign growth of the skin.
Most children develop nevi by their first birthday.
The number of nevi increases with age, tapering off around the age of 15. Children with light skin who are prone to sunburn tend to have more nevi. Nevi occur more frequently on sun-exposed areas of the body. Moles can be flat or raised. They can be round or ovoid in shape, and are usually no wider than a pencil eraser.