ABSTRACT
DEFINITION AND CLINICAL FEATURES Pigmented naevus present at birth derived from melanocytes. Congenital naevi may be divided into small (less than 1.5 cm in diameter), medium (less than 20 cm in diameter), and giant (greater than 20 cm in diameter) (377, 378). The prevalence of small congenital naevi is estimated at approximately 1% of newborn infants; giant congenital naevi are rare (less than 0.002% of infants). During infancy, naevi may be pale brown; increasing pigmentation and excessive terminal hair growth characterize older lesions. Giant naevi may be associated with underlying spinal defects, pigmentation of leptomeninges, and numerous small congenital naevi elsewhere.
