[Follow-up of a sample of 536 meningiomas seen from 1958 to 1983].

536 meningioma cases were examined in order to assess incidence in terms of sex age, site and recurrences and to discover whether recurrence was related to the site, dimensions or histological features of the tumour. The data obtained indicate that in order to assess the biological behaviour of meningiomas, their histological features, accessibility and dimensions must be borne in mind. In fact benign tumours quickly recur if they are large or inaccessible. In contrast long-term recurrences are probably due to the presence of included cells as reported in the literature.