Osteosarcoma arising from the parapharyngeal space: A case report

The current study presents a rare case of osteoblastic osteosarcoma arising from an extremely rare site, namely, the parapharyngeal space. To the best of our knowledge, this is the first study of computed tomography (CT) and magnetic resonance imaging (MRI) of an osteosarcoma in the parapharyngeal space with pathological correlation. A 56-year-old male presented with a mass of the right facial region. CT and MRI showed a heterogeneous mass, with ossification or calcification, occupying the parapharyngeal space. Open biopsy revealed an osteoblastic osteosarcoma containing calcified malignant osteoid. Lung CT also showed multiple lung metastases at the time of the first visit to the Department of Orthopedic Surgery, Osaka City University Graduate School of Medicine (Osaka, Japan). Systemic chemotherapy and radiotherapy were administered to the patient for palliation. The patient was alive at the 24-month follow-up subsequent to this treatment. Although a definitive diagnosis requires the use of a biopsy, the CT and MRI findings described in the present study suggest inclusion of this rare tumor in the differential diagnosis that is formed when such findings occur in the parapharyngeal space. The present study also briefly discusses osteosarcoma of the parapharyngeal space.