Sinus pericranii in the right frontal region and thrombosis

Sinus pericranii is a rare vascular anomaly in which an abnormal communication exists between the extracranial venous system and the underlying dural venous sinus via the diploe of the skull. We describe a case of a spontaneous thrombosis of the sinus pericranii which was located in the right frontal region and presented as a focal, leathery, and noncompressible mass distinguished in character from the typical manifestation of sinus pericranii. In this case, CT, DSA, MRI, MR venography (MRV), and pathologic examination were performed. The CT showed the bone depression in the skull and the MRI demonstrated the mass, but they were not sufficiently sensitive to detect the thrombus. Pathologic examination and MRV were helpful in depicting the thrombus. She underwent a surgical resection, and at the 5-month follow-up there was no evidence of recurrence.