Birthmark – Congenital nevus (birthmark) is a larger mole than the common ones seen in adults. It is either present at birth or appears in the first few years of life. It is tan to dark brown in color and is usually circular.
Like other moles, these are monitored for change. The ones with the greatest risk of turning into melanoma are the least common and are characterized as “giant” (larger than 20 centimeters)