Olfactory Groove Meningioma

Abstract

Anosmia is the initial clinical sign of an olfactory groove meningioma. Later on, as the tumor reaches a larger size, visual field defects and personality changes are observed. In the diagnostic studies angiography will reveal elevation and stretching of the anterior cerebral and frontal polar arteries (Figs. 140 and 141). The vascular supply comes from the anterior ramus of the middle meningeal artery and the anterior ethmoidal artery which is a branch from the usually widened ophthalmic artery. The venous phase indicates the size of the meningioma by its diffuse staining. A combined angiographic-pneumoence-phalographic study will give additional information as to the side on which the larger mass of the tumor is situated. The attachment to the floor of the anterior fossa is over the posterior cribiform plate and planum sphenoidale. Fig. 142 shows a predominantly left-sided olfactory groove meningioma extending back, depressing the optic nerve and chiasm. Its relationship to the optic nerve and chiasm is different from that of a tuberculum sellae meningioma (see p. 94, Chapter VI). The operative removal of the olfactory groove meningioma in Fig. 142 will be discussed.