Hyperpigmented nevi are brown or black moles which are present at birth, or which develop in the first year or so of life. Most congenital nevi grow with the child.  However, sometimes the lesion becomes darker especially at puberty. They may develop a bumpy surface and/or become more hairy.  Resection is recommended for any lesion with rapid growth or a change in color of the lesion.  Giant congenital hairy nevi are those nevi greater than 20cm in diameter.  Melanoma is more likely in the giant nevi (approximately 5% over a lifetime).  Tissue expansion or serial excision may be required to care for the large and giant nevi.