Intracranial low-grade chondrosarcoma with hyperostosis of the skull: a case report.

We describe a case of intracranial chondrosarcoma in a 46-year-old woman. The preoperative diagnosis was meningioma as plain radiography and computed tomography of the head revealed a tumor with discrete calcifications predominantly in the right frontoparietal region and hyperostosis of the inner table of the skull overlying the tumor. However, the tumor was histologically composed of cartilaginous tissue without meningiomatous differentiation and the final diagnosis was a low-grade chondrosarcoma based on its histological appearance and size, together with the radiologic images. Intracranial chondrosarcoma occurring above the skull base is extremely rare and 19 cases were found in our literature review. Intracranial chondrosarcoma showing hyperostosis of the skull has not been reported in the cases. The discussion includes its differential diagnosis, origin, and clinical behavior.