congenital nevus

con·gen·i·tal ne·vus

a melanocytic nevus that is visible at birth, is often larger than an acquired nevus, and more frequently involves deeper structures. Congenital nevus larger than 20.0 cm in diameter, termed giant congenital nevi, have a 6-12% lifetime risk of developing melanoma.
See also: bathing trunks nevus.

con·gen·i·tal ne·vus

(kŏn-jen'i-tăl nē'vŭs) A melanocytic nevus that is visible at birth, is often larger than an acquired nevus, and more frequently involves deeper structures.