Cemento-ossifying fibroma is a slow-growing benign non-odontogenic neoplasm, commonly enucleated from normal bone with ease. However, some lesions behave aggressively, demanding special treatment.
A 27-year-old female patient with a cemento-ossifying fibroma extending from the anterior to the right condylar process of the mandible, was presented. Although a biopsied specimen showed a ‘typical’ feature of ossifying fibroma, X-ray and CT scan showed a mixed radiolucent/radiopaque lesion with a poorly-defined margin at the ramus, suggesting aggressive behavior of the tumor. Thus, hemimandibulectomy and immediate reconstruction by autogenious iliac bone graft were performed. On histologic evaluation of the surgical specimen, multiple tumor nests were found at the ramus. In conclusion, when the lesions do not clearly fit into a known diagnostic category clinically and histologically, treatment should be based on the biological behavior of the tumor.