Desmoplastic fibroma of the mandible—rare aggressive neoplasm

Abstract

Clinical Presentation

A 34-year-old African American female patient reported an asymptomatic and expansile radiolucent lesion of unknown duration in the angle of right mandible. The panoramic image revealed a radiolucent lesion inferior to the mandibular canal with sclerotic borders. The radiolucency is located distally well below the apices of #30 and extends close to the angle of the mandible. The lesion has resulted in thinning and displacement of the lower cortical border inferiorly and the nerve canal superiorly. Cone beam computed tomography demonstrated scalloped and infiltrative margins and thinning of buccal, lingual, and inferior cortices with possible disruption in localized areas.

Differential Diagnosis

Incisional biopsy was submitted with a clinical impression of fibrous dysplasia vs low-grade malignancy.

Diagnosis and Management

Histologic examination revealed decalcified mandibular cortical bone surrounding benign cellular fibroblastic tissue proliferation arranged in intersecting cellular fascicles. The cellular proliferation was composed of fibroblast-like cells with bland elongated basophilic nuclei interspersed by dense collagen bundles. Aggregates of fibroblastic elements exhibiting stellate-shaped nuclei were noted. The host bone trabeculae exhibited resorption in areas, while osteoblastic rimming in other areas. Immunostaining was done and a diagnosis of Desmoplastic Fibroma was made. Medical computed tomography and magnetic resonance imaging were obtained. Surgical resection with a 1-cm surrounding margin of normal bone was made, followed by reconstruction.

Conclusion

Desmoplastic fibroma is a locally aggressive, nonmetastasizing fibroblastic neoplasm of mesenchymal origin. It is analogous to soft tissue deep seated fibromatosis. Metaphyseal regions of tibia and humerus are the favored sites and when jaw bones are involved, posterior mandible has a higher predilection. Radiographic features of desmoplastic fibroma may overlap with lesions including Ameloblastoma, Central ossifying fibroma, Odontogenic fibroma, Giant cell granuloma, Aneurysmal bone cyst, Fibrous Dysplasia & Fibrosarcoma. To minimize recurrence resection is the preferred treatment modality.