[Arterial sinus pericranii. First case report]

Sinus pericranii (SP) is a rare vascular anomaly consisting in an abnormal intradiploic communication between intra and extra cranial venous systems. It usually presents as a congenital soft mass in the cranial midline with progressive growth, which enlarges significantly with Valsalva maneuver. A similar congenital vascular anomaly involving intra and extra cranial arterial systems has not been previously described in the medical literature.

A 6-year-old boy with suspected midline capillary malformation of the frontal bone was referred to our Vascular Anomalies Unit for progressive increase in size. A conclusive ultrasound of high flow malformation was performed. Angio-TAC confirmed the arterial nature of the lesion and its communication with the middle meningeal artery. Embolization of the distal portion of the middle meningeal artery was performed prior to surgery. Previous to exeresis of the malformation, skin expanders were placed to cover the subsequent defect. The histopathological result was an arteriovenous malformation. Currently the patient is 10 years old and is asymptomatic, with no recurrence of the lesion.

Since its first description, SP has been classified and described in the literature as a venous malformation. Although morphologically may resemble a SP, histologically and immunohistochemically it corresponds to an arteriovenous malformation with intracranial arterial connection. It is especially important to know how to diagnose this type of cranial malformations because their long-term evolution will depend on correct management and initial follow-up.