Olfactory groove meningiomas: Pitfalls and surgical technique

Abstract

Olfactory groove meningiomas (OGMs) manifest in the midline over the cribriform plate and frontosphenoidal suture [ 8, 15, 19 ]. These tumours occupy the fl oor of anterior cranial fossa, extending all the way from the crista galli to the tuberculum sellae [ 5 ]. However, there are some similarities between posteriorly extending OGMs and tuberculum sellae meningiomas (TSMs). The most important feature distinguishing them is the location of the optic nerve in relation to the tumour. OGMs push the chiasm downward and posteriorly as they grow, whereas TSMs elevate the chiasm and displace the optic nerve superolaterally, where the tumour takes up a subchiasmal position.