Ossifying Fibroma of the Mandible – Benign Tumor with Aggressive Presentation

Abstract

Abstract Introduction/Objective Ossifying fibromas are rare benign fibro-osseous lesions of mesenchymal origin affecting the craniofacial bones. Less than 60 cases have been reported in the literature. These tumors are more commonly seen in women and are usually slow growing. Most lesions are incidental, small and treated with curettage or enucleation. Rarely, ossifying fibromas can show a rapidly growing aggressive course that require radical resection. Methods We present a case of a 63-year-old man who presented with an enlarging left mandible lesion that was first noticed two years prior. We discuss the clinical presentation, prognostic factors and management of this rare disease based on the current literature. Results The patient presented with a left mandible mass that had recently grown, caused significant pain and affected chewing. The computed tomography showed a heterogeneous sclerotic lesion with periosteal reaction of the left mandible, but no evident mass. Initial biopsy showed a bland spindle cell proliferation admixed with fragments of woven bone. Due to clinical presentation the patient underwent left hemimandibulectomy with left neck dissection. The gross examination revealed 3 x 1.5 x 0.8 cm tan-pink tumor located at the junction of the mandible body and ramus, abutting the outer bone surface. Microscopic examination showed various shaped spicules of woven bone lined by osteoblasts in a vascularized, cellular, fibroblastic and spindled cell stroma consistent with aggressive ossifying fibroma. The tumor extended into the anterior and posterior bone resection margins. All the examined lymph nodes were negative for malignancy. No adjuvant radiation or other treatment was administered. The patient is alive without evidence of disease after 7 months of follow up. Conclusion The ossifying fibroma is a rare benign fibro-osseous tumor that can rarely have an aggressive behavior. Clinical, imaging and histopathological correlation are crucial to establish the correct diagnosis. Aggressive ossifying fibromas may require radical resection to prevent recurrence.