Cemento-osseous dysplasia with a NOTCH4 mutation: a case report.

Cemento-osseous dysplasia (COD) is a benign fibro-osseous lesion of the jaw that can mimic other entities, particularly cemento-ossifying fibroma (COF), both radiologically and histologically. Although recent research has implicated mutations in the RAS-MAPK pathway in COD, its broader molecular landscape remains insufficiently defined. We report the case of a 32-year-old woman with an incidental lesion in the right mandibular angle. Radiographic assessment revealed a poorly demarcated lesion, and histopathological analysis confirmed features consistent with COD, including fibro-osseous tissue with interconnected bony trabeculae lacking osteoblastic rimming. Next-generation sequencing (TSO500 panel) identified a previously unreported NOTCH4 mutation. This finding expands the spectrum of genetic alterations associated with COD and raises the possibility of Notch signaling involvement in its pathogenesis. Incorporating molecular profiling into the diagnostic workflow may improve discrimination between COD and COF and deepen our understanding of fibro-osseous lesions of the jaw.