Abstract
Nevogenesis is a multifactorial process that involves a complex interplay of genetic and environmental factors. Growth promoting mutations (NRAS, HRAS, BRAF, and GNAQ) known to be present in various types of malignant melanoma have also been identified in benign nevi. Their presence roughly correlates with congenital, Spitz, acquired, and blue nevi, respectively. These mutations are likely to play a critical role in driving nevogenesis through activation of the MAP kinase pathway. However, mutations in these genes result in different cellular effects that cause the cells to migrate, proliferate, and differentiate to different extents within the skin. This causes each mutation to give rise to a characteristic growth pattern. Further research is necessary to fully understand nevus development given that most of the same developmental pathways are also present in melanoma.