The role of melanocytes in oral mucosa: From embryologic origin to oral mucosal melanoma: A short review

Abstract

In 1868, the Swiss embryologist Wilhelm His identified a distinctive transient embryonic cell population, the neural crest, which has been called as the “fourth germ layer” due to its importance and its capacity of giving rise to various differentiated cells types in adult organisms and it is unique in vertebrates [1].In neurulation phase of Embryogenesis, the neural tube is formed after fusion of the neural folds, and it is covered by a future epidermal ectoderm, whilst neural crest cells are positioned on its dorsal edges of the forming neural folds
Primary Oral Mucosal Melanoma (POMM) develops from malignant transformation of melanocytic cell localized in the basal layer of the oral mucosa, which incidence is between 0.2 to 8% of all melanomas, and representing 0.5% of all malignant neoplasias of the oral cavity
Neural crest cells undergo two migration pathways: ventral pathway, they migrate in the space between the somites and the neural tube and giving rise to neuronal and glial cells; Schwann cells and chromaffin cells in the adrenal medulla, whereas, dorsolateral pathway they migrate between the somite and the nonneural ectoderm and differentiating in melanoblast and melanocytes [5,6]