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BRAFV 600E mutation in the diagnosis of unicystic ameloblastoma
Author(s) -
Pereira Núbia Braga,
Pereira Karuza Maria Alves,
Coura Bruna Pizziolo,
Diniz Marina Gonçalves,
Castro Wagner Henriques,
Gomes Carolina Cavalieri,
Gomez Ricardo Santiago
Publication year - 2016
Publication title -
journal of oral pathology and medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.887
H-Index - 83
eISSN - 1600-0714
pISSN - 0904-2512
DOI - 10.1111/jop.12443
Subject(s) - ameloblastoma , mutation , medicine , pathology , dermatology , biology , genetics , dentistry , molar , gene
Background Unicystic ameloblastoma, an odontogenic neoplasm, presents clinical and radiographic similarities with dentigerous and radicular cysts, non‐neoplastic lesions. It is not always possible to reach a final diagnosis with the incisional biopsy, leading to inappropriate treatment. The BRAFV 600E activating mutation has been reported in a high proportion of ameloblastomas. The purpose of the study was to assess the utility of the detection of the BRAFV 600E mutation in the differential diagnosis of unicystic ameloblastoma with dentigerous and radicular cysts. Methods Twenty‐six archival samples were included, comprising eight unicystic ameloblastomas (UAs), nine dentigerous and nine radicular cysts. The mutation was assessed in all samples by anti‐ BRAFV 600E (clone VE 1) immunohistochemistry ( IHC ) and by TaqMan mutation detection qPCR assay. Sanger sequencing was further carried out when samples showed conflicting results in the IHC and qPCR . Results Although all UAs (8/8) showed positive uniform BRAFV 600E staining along the epithelial lining length, the mutation was not confirmed by qPCR and Sanger sequencing in three samples. Positive staining for the BRAFV 600E protein was observed in one dentigerous cyst, but it was not confirmed by the molecular methods. Furthermore, 2/9 dentigerous cysts and 2/9 radicular cysts showed non‐specific immunostaining of the epithelium or plasma cells. None of the dentigerous or radicular cysts cases presented the BRAFV 600E mutation in the qPCR assay. Conclusions The BRAFV 600E antibody (clone VE 1) IHC may show non‐specific staining, but molecular assays may be useful for the diagnosis of unicystic ameloblastoma, in conjunction with clinical, radiological and histopathological features.