Intracranial Arteriovenous Malformation Embedded in a Meningioma – Case Report and Review of the Literature
Introduction: Association between arteriovenous malformation (AVM) and meningioma is a rare occurrence intracranially. Most reports document cases in which the tumor is obstructing venous outflow with associated dural arteriovenous fistula.
Case Description: A 59-year-old man presented with a right parietal extra-axial mass. 5 years prior, he was treated medically for a right sided subdural hematoma and right convexity and sylvian subarachnoid hemorrhage sustained in a motor vehicle accident. Preoperatively, hemangiopericytoma was suspected on the basis of an unusually vascular pattern. Angiography revealed abnormal vascular structures associated with the lesion and the presence of an early draining vein. Arterial feeders to both lesions were primarily from the middle cerebral artery with discrete contribution from the middle meningeal artery. Craniotomy and Simpson I resection of the lesion was undertaken and revealed the coexistence of a meningioma with an AVM that presented an intraparenchymal nidus.
Discussion: The absence of significant mass effect on the venous system in the present case supports the theory that other pathophysiological mechanisms, in addition to venous outflow obstruction, may lead to development of an acquired AVM. Increased blood flow in the vicinity of the meningioma and the presence of increased levels of angiogenic factors have been previously mentioned. On the contrary, a congenital AVM, associated with the occurrence of a haemorrhagic event, may well have contributed to the development of the meningioma.