[Cystic meningioma. An aspect of "forme humide" of Masson].

The presence of a no haemorragic cystic cavity in to a meningioma is a rare event. It has different pathogenetic mechanisms. It can sometimes, be the result of a wide necrotic area as it is frequently observed in the meningoblasomas that have had an extensive vascular developments. In our three cases the cystic cavity seems to be the result of a particular vacuolar and mixomatosa degeneration of the neoplastic tissue. Our cystic meningiomas are similar to damp meningioma of Masson.