[Pericranial sinus. Definition, diagnosis, surgical treatment].

Pericranial sinus (Sinus pericranii - SP) is a rare pathology of the extra-intracranial cerebral venous system. However, SP is not just an additional transosseous canal that connects the extra- and intracranial venous systems. This "emissary vein" connects the intracranial sinus and the variceally extended thin-walled veins localized on the outer surface of the skull where blood flows fun in opposite directions. We present a literature review and two case reports of patients with pericranial sinus who underwent surgical treatment. We discuss the problems related to etiology, clinical signs, diagnosis, and surgical treatment of the anomaly.