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The Scientific World Journal
Volume 2017 (2017), Article ID 9189812, 7 pages
https://doi.org/10.1155/2017/9189812
Review Article

A Review of the Aetiopathogenesis and Clinical and Histopathological Features of Oral Mucosal Melanoma

Department of Periodontology and Oral Medicine, Sefako Makgatho Health Sciences University, Medunsa, Pretoria 0204, South Africa

Correspondence should be addressed to Liviu Feller; az.ca.ums@rellef.uivil

Received 6 January 2017; Accepted 20 April 2017; Published 30 May 2017

Academic Editor: Stefania Staibano

Copyright © 2017 Liviu Feller et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Oral mucosal melanoma is an uncommon, usually heavily melanin-pigmented, but occasionally amelanotic aggressive tumour with a poor prognosis. Despite radical surgery, radiotherapy, or chemotherapy, local recurrence and distant metastasis are frequent. Microscopical examination is essential for diagnosis, and routine histological staining must be supplemented by immunohistochemical studies. The aetiology is unknown, the pathogenesis is poorly understood, and the 5-year survival rate rarely exceeds 30%. In most cases, oral mucosal melanoma arises from epithelial melanocytes in the basal layer of the epithelium and less frequently from immature melanocytes arrested in the lamina propria. In both cases the melanocytes undergo malignant transformation, invade deeper tissues, and metastasize to regional lymph nodes and to distant sites. Very rarely metastasis from skin melanoma may give rise to oral mucosal melanoma that may be mistaken for primary oral mucosal melanoma. The pathogenesis of oral mucosal melanoma is complex involving multiple interactions between cytogenetic factors including dysregulation of the cKit signalling pathways, cell cycle, apoptosis, and cell-to-cell interactions on the one hand and melanin itself, melanin intermediates, and local microenvironmental agents regulating melanogenesis on the other hand. The detailed mechanisms that initiate the malignant transformation of oral melanocytes and thereafter sustain and promote the process of melanomagenesis are unknown.