BackgroundTorcular meningiomas involving major dural venous sinuses are rare entities and a great challenge for neurosurgeons. The deep knowledge of the patency of occlusion of the sinuses, the extent of the occlusion and potentially new developing of extra and intracranial collateral venous drainage as compensatory venous channels, are at the base of a correct operative strategy.Case DescriptionA 45-year-old woman presented with persistent headache. Magnetic resonance imaging of the brain and digital subtraction angiography demonstrated a huge torcular meningioma with complete multi-venous sinus occlusion and a wide venous network for brain and tumor drainage. In these rare cases, we have hypothesized the presence of venous drainage shared by the brain and the tumor, which could generate undesirable venous occlusion during operative resection. This could be a cause of the well-known …