Malignant Meningioma: Two Cases Observed at the Hospital Center of Soavinandriana, Antananarivo

Introduction: Meningiomas are tumors formed by arachnoid cells, typically attached to the inner surface of the dura mater. Malignant forms are rare and no case has been reported in the Malagasy literature. The objective of our study is to report two Malagasy cases of malignant meningioma and to discuss the epidemiological and anatomical-clinical particularities of this tumor. Observation: The first patient, a 41-year-old woman, presented with a rapidly progressive intracranial hypertension syndrome. The patient had undergone surgery two years earlier for a grade II meningioma and had no family history of meningioma, neurofibromatosis, or personal history of brain irradiation or head trauma. Her brain scan showed a heterogeneous polylobed left parieto-occipital mass with a meningeal implantation base. The anatomopathological examination of the samples revealed a malignant meningioma. The second patient was a 33-year-old man, operated for grade I meningioma eleven months before admission, with no other personal or family history. The patient was hospitalized for tumor recurrence with signs of intracranial hypertension. The brain computed tomography (CT) scan showed a heterogeneous extra-axial tumor in right temporo-parietal lobe. Surgical excision was performed. On histological examination, a proliferation of tumor cells of meningothelial appearance with papillary architecture was observed, leading to the diagnosis of malignant meningioma. Conclusion: Malignant meningioma is a rare and serious entity. The clinical manifestations are nonspecific and imaging may mimic a low-grade meningioma. The diagnosis of certainty is histological and is based on essentially morphological criteria. The latter condition the overall survival of the patient and the therapeutic conduct.