OLFACTORY GROOVE MENINGIOMAS – CLINICAL PRESENTATION, TREATMENT AND OUTCOMES

Olfactory groove meningiomas are benign tumors, which arise in the midline of the anterior cranial fossa, over the cribriform plate and frontosphenoid suture. They represent approximately 10 percent of all intracranial meningiomas, more likely to occur in women in the fifth and sixth decades of life. They often involve the area from the grista galli to the posterior planum sphenoidale, and can be either simetric, bilateral or unilateral based on their midline origin. We report the case of a 45-year-old man who presented with an episode of loss of consciousness, progressive mental disturbances, impairment of visual acuity, anosmia and headache. Gadolinium-enhanced T1-weighted MR images showed a well-defined, hyperintense mass, located in the anterior cranial fossa, measuring 45/50/61 mm, with homogenous enhancement and a broad dural attachment to the cribriform plate, from crista galli to the planum sphenoidale. Preoperative Angiography revealed tumor vascularization from anterior and posterior ethmoidal arteries, branches of ophthalmic artery and branches of external carotid artery. The olfactory groove meningioma was successfully resected using a bifrontal approach with frontal sinuses opened in order to avoid brain retraction. Cranialization with pericranium of frontal sinuses was performed at the end of surgical procedure. Improvement of visual acuity was noted, mental disturbances and seizures remitted, but cerebrospinal leakage occurred, resolved via recranialization of frontal sinuses and lumbar punctions. The last postoperative computer-tomography investigation showed total surgical removal with no recurrence or residual tumor. Total tumor removal must be performed with coagulation of its arachnoid attachments and resection of hyperostotic bone in order to avoid recurrence, but with least brain retraction.