Moles, also called “melanocytic nevi,” are common in newborns and infants (about 1 percent).
If they are seen at birth or develop during the first 1-2 years of life they are called congenital melanocytic nevi. While most of these moles are small, some may be very large. Most of these will grow as your child grows.
Melanocytic nevi usually look like light to dark brown spots on the skin. In children with very light or fair skin, they may appear more pink or red in color. They may have hair growing in them, a bumpy texture, or slowly get darker in color; such changes are generally normal.
Most congenital melanocytic nevi do not need treatment. However, all moles carry a very small risk for the development of melanoma, a type of skin cancer. The development of melanoma within a congenital melanocytic nevus is very rare.
However, children with a large congenital melanocytic nevus are at a higher risk for melanoma and for another condition called “neurocutaneous melanosis.” In neurocutaneous melanosis, there are too many pigment cells (called melanocytes − meh-lan-uh-site) in the brain and/or spinal cord. This can lead to seizures, developmental delays, or other neurological issues. Your doctor may order an MRI (imaging study) to look for these pigment cells.
Congenital melanocytic nevi do not go away with time. Some congenital melanocytic nevi may get lighter in color over the first few years of life.