[Meningiomas: present and future]

The article describes the most recent advances in the field of the embryology, physiopathology, therapy, and prognosis of meningiomas. It is assumed that the future of our knowledge of these neoplasms will be based upon the present basic and clinical research. The well known arachnoid cell origin of meningiomas is emphasized, the ultrastructure of the arachnoid villi is mentioned and the double embryological origin of the meningeal membranes--neuroectodermal and mesodermal--is stressed. Based upon personal ultrastructural and immunohistochemical studies, the probable pericytic and arachnoid origin of the so-called hemangiopericytic and sarcomatous meningiomas respectively, is reported. The several possible physiopathological mechanisms of the peritumoral oedema are summarized. Concerning the biological behaviour of meningiomas, the relevance of complete surgical resection is stressed, although new imaging or histological technics are also important in the prediction of recurrences. Lastly, regarding the management of these kind of tumors, other therapeutic procedures beyond surgery are also considered.