Sinus pericranii with unusual features: multiplicity, associated dural venous lakes and venous anomaly, and a lateral location

Anomalous connections between an extracranial venous sac and intracranial dural sinuses through dilated diploic and emissary veins of the skull result in sinus pericranii (SP). In this study, two patients with the rare presentation of multiple, congenital SP with associated dural venous lakes and venous anomalies are described. In one patient, multiple SPs were located in the frontal, parasagittal region with an associated subcortical venous angioma; and, in the other, peritorcular and juxta–transverse–sigmoid sinus junction SP coexisted. The venous anomalies drained into venous lakes in close proximity to major sinuses. They also communicated with extracranial tributaries via interosseous veins leading to the development of venous hypertension that presumably caused pressure erosion of the skull. This may have been responsible for the pathogenesis of multiple subgaleal venous sacs of SP and may also lead to profuse hemorrhage, cortical venous thrombosis, or air embolism. Multiplicity, associated venous lakes, venous angioma, and a lateral location are unique presentations of SP. Sac excision, transcranial venous anastomotic channel blockage, and reinforcement/replacement of the underlying bone are the recommended modalities of treatment.