Sinus pericranii, a rare venous anomaly in the superior eyelid

Introduction Sinus pericranii (SP) is a rare venous malformation, by which there is an aberrant transosseous connection between the intracranial venous sinuses and the epicranial veins. Within the aberrant vein, the blood flow could be bidirectional. If the major venous drainage occurs through the SP, it is classified as dominant. And it"s considered an accessory, if the SP marginally contributes to the venous drainage of the brain.