[Isolated ethmoid meningioma. Apropos of a case].

A case of meningioma confined to the ethmoid region is reported. After emphasizing the rare nature of these primary localizations, and their clinical latency, a brief summary is given of the embryologic origin of these tumors. Comparison of the long-term course of double-sac meningiomas and those developing primarily in the ethmoid region showed improved prognosis for the latter, following total surgical excision, the former having a very marked tendency to recur.