Primary osteosarcoma of frontal bone

Rationale:Primary osteosarcomas of the skull and skull base are rare, comprising<2% of all skull tumors. Primary osteosarcomas of the skull are aggressive neoplasms composed of spindle cells producing osteoid which have poor outcome. Patientconcerns:A 33-year-old woman was admitted to our hospital with a major complaint of a growingmass on her left frontal region of the skull for 10 months. Prior to the accurate diagnosis, the mass on her skull was considered to be eosinophilic granuloma. Diagnoses: Computerized tomogram (CT) scan of skull revealed a lytic lesion causing destruction of left frontal bone with surrounding soft tissue mass. The histological examination of the lesion showed typical features of osteosarcoma. Interventions: The patient received 3 surgeries and adjuvant chemotherapy and radiotherapy for the frontal bone lesion. Outcomes:At the last follow-up, after 4 years, the patient was free of disease both clinically and on imaging bymagnetic resonance imaging (MRI) scan after 4 years. Lessons: Because osteosarcoma of skull is a rare disease, the early recognition and correct diagnosis are very important for a better prognosis. It is therefore imperative that clinicians recognize osteosarcoma early to make an accurate diagnosis and complete surgical resection followed by combined chemo-radiation is proved to be one of the most optimal treatment regimens. Abbreviations: CT= computerized tomogram,MDP=methylene diphosphonate, MRI=magnetic resonance imaging, SPECT= single photon emission computed tomography.