Acquired Sinus Pericranii Due To Parasagittal Meningiomatous Invasion of the Superior Sagittal Sinus and Bilateral Transverse Sinuses.

Background Sinus pericranii is a rare vascular anomaly characterized by abnormal connections between the extra- and intracranial venous systems. Although the etiology still remains unclear, sinus pericranii is usually congenital in nature, or less likely may be secondary to spontaneous or traumatic causes. Case Description We present a unique case of spontaneous sinus pericranii secondary to a parasagittal meningioma invading and occluding the superior sagittal sinus, torcula herophilii, and bilateral transverse sinuses. The resultant venous outlet obstruction and venous hypertension may have been the inciting factors for the development of the collateral channel connecting the intra- and extracranial venous systems. Conclusions This case highlights the effect of the reversal of normal venous outflow secondary to meningiomatous occlusion of intracranial dural sinuses. Sinus pericranii may, on rare occasions, represent the sole means for intracranial venous drainage in cases of intracranial venous thrombosis or incomplete development of the cerebral venous system. Therefore, this case also highlights the importance of pretreatment evaluation of the venous drainage system in patients with sinus pericranii and those with meningiomas.