BRAF p.V600E status in epithelial areas of ameloblastoma with different histological aspects: Implications to the clinical practice.

Journal of oral pathology & medicine : official publication of the International Association of Oral Pathologists and the American Academy of Oral Pathology 2021 May

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BRAF p.V600E is reported in up to 80% of ameloblastomas. Despite the high frequency, the presence of this mutation in different histopathological areas of the tumour has not been investigated. This information has an important role in the use of BRAF p.V600E assessment as an auxiliary tool in the differential diagnosis between unicystic ameloblastoma and other odontogenic cystic lesions, especially when only incisional biopsies are available. Therefore, the purpose of the present study was to investigate BRAF p.V600E heterogeneity in unicystic ameloblastoma. Five cases of ameloblastoma and two dentigerous cysts were analysed. The regions exhibiting different microscopic characteristics were selected from each ameloblastoma case and manually dissected. TaqMan allele-specific qPCR or Sanger sequencing was performed to determine BRAF p.V600E status. We screened the mutation in a small cohort of UA and no molecular heterogeneity was found. Four cases of ameloblastoma (80%) exhibited BRAF p.V600E in all different areas evaluated. One case did not harbour the mutation in any microscopic region analysed. The BRAF mutation was absent in the dentigerous cysts. Ameloblastomas appear to exhibit a homogeneous profile regarding the BRAF p.V600E no matter what histological feature is observed under light microscopy, suggesting that this molecular test may contribute to establish the correct diagnosis in cases microscopically resembling other odontogenic lesions. © 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Citation

Maria Sissa Pereira Sant'Ana, Sara Ferreira Dos Santos Costa, Maísa Pereira da Silva, Roberta Rayra Martins-Chaves, Thaís Dos Santos Fontes Pereira, Eduardo Morato de Oliveira, Ricardo Martínez Pedraza, Wagner Henriques de Castro, Carolina Cavaliéri Gomes, Ricardo Santiago Gomez, Felipe Paiva Fonseca. BRAF p.V600E status in epithelial areas of ameloblastoma with different histological aspects: Implications to the clinical practice. Journal of oral pathology & medicine : official publication of the International Association of Oral Pathologists and the American Academy of Oral Pathology. 2021 May;50(5):478-484