{Reference Type}: Case Reports {Title}: Adenoid Ameloblastoma with BRAF p.V600E Mutation Revealing Ameloblastomatous Origin: A First Case Report. {Author}: Noda Y;Sawada S;Sakagami T;Kojima Y;Higasa K;Tsuta K; {Journal}: Head Neck Pathol {Volume}: 17 {Issue}: 3 {Year}: 2023 Sep 24 ĉš‚ĉ— {DOI}: 10.1007/s12105-023-01555-9 {Abstract}: BACKGROUND: Adenoid ameloblastoma (AdAM) is a frequently recurrent tumor that shows hybrid histological features of both ameloblastoma and adenomatoid odontogenic tumor (AOT). AdAM is expected to be classified as a new subtype of ameloblastoma in the next revision of the World Health Organization (WHO) odontogenic tumor classification. However, whether AdAM is a histologic variant of ameloblastoma or AOT remains unclear. To establish a new category, genetic evidence indicating the tumor category is necessary.
METHODS: We present a case of a 23-year-old Japanese woman with AdAM who underwent genetic/DNA analysis for ameloblastoma-related mutation using immunohistochemical staining, Sanger sequencing, and next-generation sequencing (NGS) analyses with reliable clinicopathological evidence.
RESULTS: Immunohistochemical expression of BRAF p.V600E was diffusely positive for both ameloblastoma- and AOT-like components. Sanger sequencing and NGS analyses showed missense mutations in BRAF p.V600E (c.1799T > A), a gene that is commonly altered in ameloblastomas but not in KRAS, another gene associated with AOT.
CONCLUSIONS: This case report is the first to provide genetic evidence on the ameloblastomatous origin of AdAM with a BRAF p.V600E mutation. A larger series of AdAM groups' molecular testing is needed to aptly classify them and prognosticate the best treatment.