Ameloblastic Fibro-Odontoma with an FGFR1 Mutation: A Case Report.

PURPOSE: Ameloblastic fibro-odontoma (AFO) is a rare benign mixed odontogenic tumor that, after being classified for years as a distinct entity, was redefined as a "developing odontoma" in the 2017 World Health Organization classification. This article presents a unique case of an AFO with an FGFR1 mutation. METHODS: We present a case of an 8-year-old child with a slowly progressive swelling in the lower left mandible. Next-generation sequencing (TSO500 panel) was performed. RESULTS: Panoramic radiography revealed an odontogenic tumor; therefore, a transoral enucleation was performed. Pathological microscopic examination confirmed the diagnosis of AFO, and next-generation sequencing detected an FGFR1 mutation. CONCLUSION: The presence of an FGFR1 mutation in an AFO may suggest a closer biological relationship between ameloblastic fibroma and AFO, potentially distinguishing it from odontomas. Further research, including genetic studies, is needed to enhance our understanding and refine the classification of these tumors.