This 16-year-old girl was evaluated for a congenital medium sized, dark brown plaque containing prominent dark hairs. Congenital nevi appear at birth or shortly thereafter in 1% of newborns. Large congenital nevi, greater than 20 cm in diameter, are associated with a 2.5-12% risk of developing melanoma. Small congenital nevi, which are less than 2 cm in diameter, and medium-sized congenital nevi, which are between 2 cm and 20 cm in diameter, have little or no increased risk of transformation into melanoma. Approximately 50% of small and medium- ized congenital nevi become hairy over time, and this does not change the generally good prognosis.
5 X 8 cm well demarcated uniformly dark brown pigmented plaque with prominent dark pigmented hair