Malignant meningioma with extracranial metastases.

Dr. Baltazar Leão Reis – Avenida Francisco Sales 1813 / 102 30150-221 Belo Horizonte MG Brasil. E-mail: [email protected] Meningiomas are tumors originating from meningothelial cells of the arachnoid membrane and are benign in most cases, corresponding to about 15% to 18% of all primary tumors of the central nervous system (CNS). Extracranial metastases of meningiomas are rare and occur in less than 1 per 1000 cases. According to the WHO criteria, the histological grade of the tumor is the most important predictive factor of malignancy. Anaplastic meningioma histologically corresponds to WHO grade III and shows overt signs of malignancy accompanied by a high rate of mitosis and abundant necrosis. In addition, this form is characterized by intense cerebral invasion. The exact definition of malignant or anaplastic meningioma is still a matter of discussion. One factor that undoubtedly defines malignant meningioma is the occurrence of extraneural metastases. However, according to some investigators, the occurrence of distant metastases is not an unequivocal sign of histological malignancy. We report a case of a 75-year-old man with malignant meningioma who presented extracranial metastases.