EGFR T790M Mutations in Conventional and Langerhans Cell-Rich Variants of CEOT: Unveiling Molecular Differences and Clinical Implications.

OBJECTIVES

We aimed to investigate the clinicopathologic and molecular characteristics of conventional and Langerhans cell-rich (LC-rich) variants of Calcifying Epithelial Odontogenic Tumor (CEOT).

METHODS

Fifteen patients, eight with conventional and seven with LC-rich variants, were analyzed using clinical data, radiographic features, and histopathologic assessments. A 560-gene cancer panel, utilizing Agilent probe hybrid capture technology, was employed for next-generation sequencing (NGS) to detect genetic mutations. The EGFR c.2369C>T (p.T790M) mutation was identified and further validated using droplet digital PCR (ddPCR).

RESULTS

Our findings revealed that conventional CEOT primarily occurred in the mandible, with 75% displaying the EGFR c.2369C>T (p.T790M) mutation. Conversely, the LC-rich variant was more prevalent in the maxilla, with 28.57% exhibiting the same mutation. Radiographic patterns showed distinct differences, with the LC-rich variant demonstrating more aggressive clinical behavior.

CONCLUSIONS

The identification of EGFR c.2369C>T (p.T790M) mutations in both variants underscores its significant role in CEOT pathogenesis and suggests potential implications for targeted therapies. This comprehensive analysis enhances our understanding of the molecular landscape of CEOT variants and highlights the necessity for tailored diagnostic and treatment strategies.