Osteosarcoma of the skull base: case report and review of literature.

Osteosarcoma is the most common primary malignancy of bone in children and adolescents. Osteosarcomas are an aggressive neoplasm composed of spindle cells producing osteoid. They primarily affect the long bones, particularly after radiation or chemotherapy for other neoplasms; however, 6-7% present in the head and neck. Primary head and neck osteosarcomas in children are rare. There are few case reports and limited-sized case series in the literature. A case report presentation of a skull base osteosarcoma in a teenage female. A 14-year-old African American female presented with dysphagia, voice changes, and neck pain. On examination, she had right-sided palsies in cranial nerves X, XI, and XII. Imaging revealed partial enhancement of the clivus without bony erosion and expansion of the hypoglossal canal. There were also findings consistent with chronic denervation of her right tongue and pharynx. During the evaluation process, she developed diplopia from a right cranial nerve VI palsy. Repeat imaging revealed progression of the skull base lesion with extension into the right sphenoid sinus. An endoscopic sphenoidotomy was performed to obtain tissue. The diagnosis of high-grade osteosarcoma was made by histologic morphology and immunohistochemistry. The child was treated primarily with chemotherapy. Other adjunctive therapies are being considered. Osteosarcoma of the skull base is a rare entity. We describe a case of a high-grade clival osteosarcoma presenting primarily with lower cranial nerve palsies and pain. The rapid progression, treatment options, and prognosis are discussed.