Frontal Mass That Varies in Size With Body Position: A Surgical Treatment of a Rare Case of Sinus Pericrania.

Sinus pericranii (SP) is a vascular malformation characterized by abnormal communication between extracranial scalp venous channels and intracranial sinuses. Owing to its rarity, it is prone to misdiagnosis and mistreatment. A typical characteristic of SP is that the size of the mass is related to its position. To date, there are no uniform criteria for SP treatment options and prognosis. This article reports an innovative surgical method for the complete cure of an adult frontal SP. The authors systematically displayed the extracranial, cranial, and intracranial parts of the SP, and the authors found that not only the venous sinus is involved in the SP but also the draining veins on the dura mater can be involved in the formation of the SP. The authors' report reviews the understanding of SP-related intracranial veins and proposes a method to block its anatomic pathology and achieve a clinical cure.