Abstract: Congenital pigmented nevus, also known as congenital melanocytic nevus (CMN), appears at birth or shortly after birth and has unique clinical and histopathological characteristics. According to the size, congenital nevus can be divided into the following four types: small nevus, medium nevus, large nevus and giant nevus. It is estimated that about 1% of newborns have congenital nevi, most of which are small/medium nevi, and large/giant nevi are rare. This article summarizes the progress of congenital pigmented nevus from the aspects of clinical, complication, pathology, gene and treatment, in order to improve the level of clinical diagnosis and treatment.

Key words: congenital melanocytic nevus, NRAS, BRAF, neurocutaneous melanosis, melanoma