Congenital nevus is a type of melanocytic nevus (mole) found in infants at birth. Often times is located in the area of the neck or head.
A mutation in the body’s cell’s occuring in the early stages of development is estimated to be the cause however there is not a known method of prevention.
It is possible that congenital nevi degenerate into melanoma are most commonly considered to be at the low end of that spectrum. Larger congenital nevi are at greater risk for malignancy degeneration into melanoma.