MENINGIOMA OF THE PINEAL REGION - A SURGICAL SERIES OF 10 CASES

Ten cases of meningioma of the pineal region were histologically verif ied at a single institution during an 8-year period. These represented 0.3% of 3061 intracranial meningiomas, as well as 6.2% of 164 pineal tumors. patients were predominantly women. Symptoms and signs of incre ased intracranial pressure were most common, whereas Parinaud's syndro me was observed in only one case. Computerized tomography (CT) was the main diagnostic test used in the present series. It usually revealed a hyperdense mass with high-intensity contrast enhancement and a calci fied mass eccentrically located at the periphery, which returned to it s central location postsurgically and was likely to represent a calcif ied pineal gland. Magnetic resonance imaging was performed in the more recent cases and confirmed the suspicion raised by CT of a meningioma with a calcified mass at its periphery. Surgery was performed using a n occipital transtentorial microsurgical approach with the patient pla ced in the semisitting position. Gross-total tumor removal was achieve d in all cases, although this required sacrifice of the vein of Galen in six patients. Venous occlusion was performed only after adequate in traoperative verification of functional occlusion and blood flow diver sion from the galenic system and had no consequences in any case but o ne. This latter patient had an infiltrative meningioma that was remove d at the expense of intraoperative sacrifice of the two internal cereb ral veins, as well as unavoidable trauma to the region of the quadrige minal plate. All the remaining patients improved postsurgery, and only one had a permanent visual field deficit as a result of the surgical approach. Pineal meningiomas represent a rare subgroup of pineal tumor s that can be treated surgically with reasonably good results. Sacrifi ce of major basal veins may be required to achieve radical tumor remov al and can he tolerated by the patient provided that functional occlus ion of the galenic system, as indicated by preoperative angiography, i s verified during surgery.