Radiation‐induced osteosarcoma involving the mandible—Report of a rare diagnosis

Abstract

AbstractBackgroundRadiation‐induced osteosarcomas of the jaws are a rare but often fatal consequence of radiation therapy in the head and neck region. Here we present a case of radiation‐induced osteosarcoma of the mandible.Case PresentationA male presented with severe trismus and marked left lingual alveolus expansion 1 year following extractions in the lower left quadrant. Four years previously, he had radical radiotherapy (70Gy) and chemotherapy for a p16‐positive T1N2cM0 squamous cell carcinoma of the left tonsil with a positive left level II node. Initial bone biopsies of the left mandible showed a bony sequestrum suggestive of osteoradionecrosis with the presence of abnormal osteoid suspicious of osteosarcoma. Imaging demonstrated an abnormal exophytic bone‐forming lesion in the left mandibular body and parasymphysis and ruled out a metastatic lesion. The patient underwent bilateral neck dissection, left mandibulectomy with fibula flap reconstruction and full‐thickness skin graft.ConclusionsOsteosarcoma should be considered if changes are seen in previously stable irradiated bone with bony destruction and a soft tissue mass. This case highlights the importance of synthesis of clinical, radiological and pathological findings in the diagnosis of such lesions, especially where the histology initially suggested a benign process.