Pathogenesis and clinicohistopathological caractheristics of melanoacanthoma: A systematic review.

INTRODUCTION: The melanoacanthoma is a rare benign pigmented tumor, characterized by a fast radial growth and clinical behavior similar to melanoma. Color changes in oral mucosa and dermis are consequence of increased melanocyte activity as response to an irritant factor. There is a vast phenotypic variety. It is difficult to distinguish between a benign pigmented lesion and a melanoma at its early stage. Due to its clinical relevance is crucial to diagnose possible malignancy of the lesions.

OBJECTIVES: The aim of this article is to conduct a systematic review of all published articles, as well as update and evaluate etiologic factors and clinicopathological features.

MATERIAL AND METHODS: We carried out a search in the Medline database (PubMed) using the key words "oral melanoacanthoma" AND "oral melanoacanthosis" AND "oral melanoepithelioma". Inclusion criteria were all published articles since its discovery. Demographic data, histological features and immunohistochemical findings were extracted from the full articles.

RESULTS: A total of 56 articles were analysed. 114 injuries drawn from these articles were studied, a total of 115 injuries with our contribution case. The 74.78% of authors claim a reactive pathogenesis. The average age of lesión appearance is 34.79 years, with an age range of 5-87 years. There is a predominance of the female sex in solitary phenotype 3: 2 and a ratio of women to men 5: 3 if it is multifocal phenotype. Bilateral phenotype is slight higher in women of 2: 1.

CONCLUSIONS: Histopathological analysis of the lesión is vital to diagnose malignancy. Therefore, any heterogeneous, pigmented lesion with irregular edges, raised surface, fast growth and abrupt appearance should be biopsied. More emphasis on the potential irritants should also be put to improve the quality of life of our patients and to reduce morbidity of melanoacanthoma, as well as, several similar clinical behavior disease.

KEY WORDS: Melanoacanthoma, oral cáncer, diagnosis.