Peripheral odontogenic fibroma of the mandible

OBJECTIVES Odontogenic fibroma (OF) is a rare benign neoplasm of mature fibrous connective tissue, with variable amounts of inactive-looking odontogenic epithelium, with or without evidence of calcification. Two clinical variants are described: intra-osseous or central odontogenic fibroma and extra-osseous or peripheral odontogenic fibroma. The aim of the present article is to present and discuss a case of peripheral odontogenic fibroma. MATERIALS AND METHODS A 63-year-old man presented with a history of a swelling in correspondence of the left mandibular body for 2 years. He had not experienced pain or other symptoms in the left mandibular region at any time. There was no previous trauma. The lesion was painless and had progressively increased in size. A panoramic radiograph and CT scans confirmed the presence of a mixed radiolucent-radiopaque area in the left mandibular body, in correspondence of the edentulous upper cortical border, posteriorly to the left inferior canine. An incisional biopsy of the lesion was decided. Histological examination together with clinical and radiological findings allowed to establish the diagnosis of peripheral odontogenic fibroma. Therefore, the excision of the odontogenic fibroma was performed under local anesthesia. DISCUSSION The etiology of odontogenic fibroma remains unclear, although a role by developmental defects in normally quiescent genomes, which then trigger oncogenic mutation pathways, has been proposed. The clinical and radiographic differential diagnosis includes cysts of odontogenic origin, calcifying epithelial odontogenic tumour (Pindborg tumour), adenomatoid odontogenic tumour, ameloblastic fibroma and ameloblastoma. Histopathological examination is crucial to obtain the appropriate diagnosis. CONCLUSIONS Dental practitioners should be aware of the unusual nature of this lesion, include it in the differential diagnosis of intrabony tumors of the jaws, help establish a correct diagnosis, and give the appropriate therapeutic management. CLINICAL SIGNIFICANCE The gold standard of treatment of central OF is enucleation and curettage, which sometimes requires removal of adjacent involved teeth.