Case Report: Prenatal ultrasound presentation of congenital melanocytic nevus syndrome.

Congenital melanocytic nevus (CMN) syndrome is a rare, non-familial neural ectodermal dysplasia characterized by CMN combined with extracutaneous abnormalities, predominantly involving the central nervous system (CNS). The pathogenesis of CMN syndrome is thought to result from early post-zygotic somatic mutations. CNS melanosis frequently affects the anterior temporal lobes, brainstem, cerebellum, and cerebral cortex.