Bleomycin electroembolotherapy in a rare mixed extra- and intracranial scalp-dural vascular malformation with high-...

A rare extra- and intracranial mixed vascular malformation involving the scalp soft tissues and the dura mater, associated with skull erosion, and characterized by both a low-flow capillary-venous component and a high-flow component consistent with a dural arteriovenous fistula involving a diploic vein, represents a complex therapeutic challenge. An 18-year-old man underwent multimodal imaging for evaluation of non-disabling headaches and intermittent pulsatile sensation. MRI and CT demonstrated focal calvarial erosion, while MRA and digital subtraction angiography revealed a direct shunt between the middle meningeal artery and a diploic vein, in addition to a diffuse low-flow capillary-venous network supplied by branches of the external carotid artery and the middle meningeal artery. Treatment consisted of selective embolization of the shunt using n-butyl cyanoacrylate, followed by intra-arterial bleomycin administration combined with reversible electroporation targeting the slow-flow component. At 6-month follow-up, the patient was asymptomatic, with only localized alopecia at electrode application sites. Follow-up MRI demonstrated near-complete resolution of the dural component and marked reduction of the extracranial lesion, indicating a favorable clinical and radiological outcome.