Olfactory Groove and Suprasellar Meningiomas

Abstract

Meningiomas of the central subfrontal region originating either from the olfactory groove, planum or jugum sphenoidale or suprasellar area, account for about 10% of all meningiomas in a review of the world literature (Cushing and Eisenhardt 1938, Ehlers and Malmros 1973, Fusek and Kunc 1969, Guillaumat 1937, Olivecrona 1967, Zülch 1956), and they are therefore relatively uncommon lesions in general neurosurgical practice. Close association with clinics of ophthalmology, however, increases the referral rate of these interesting lesions. As in most meningiomas, a number of terms have been used to describe their site of origin. The general term, subfrontal, is often regarded as synonomous with the meningiomas arising from the olfactory groove; where the origin can be specified as from the planum or jugum of the sphenoid bone, these sites may be specified; meningiomas arising from one anterior clinoid may be described; and meningiomas arising from the dorsum sellae or from the diaphragma sellae constitute the true suprasellar meningiomas. This paper will deal, in the main, with those arising from the olfactory groove and from the jugum sphenoidale (tuberculum sellae) or from a mixture of the two, and while the latter group are frequently termed suprasellar meningiomas, the author prefers the term “meningioma of the jugum sphenoidale” since that more nearly describes their site of origin. As in most meningiomas, the attribution of a primary site of origin to a large tumour may be extremely difficult, and while these two main groups—the olfactory groove and the jugum tumours—tend to run true to type, extension laterally along the sphenoidal wing does occur from time to time, thereby increasing the difficulty of classification and also, incidentally, the difficulties of removal of the tumour.