Unique Extrancranial-to-Intracranial Neovascularization Found on Diagnostic Angiography Prior to Skull Base Atypical Grade 2 Meningioma Resection: A Case Report and Hypothesis.

Meningiomas are common intracranial tumors that can have a complex arterial supply. In a patient with a recurrent large left clinoid aypical grade 2 meningioma, diagnostic angiography revealed left proximal middle cerebral artery (MCA) occlusion and reconstitution of the MCA circulation from the left middle meningeal artery. Consequently, the planned surgical approach was adjusted to preserve the left external carotid artery circulation in a difficult meningioma resection. This case illustrates a role for preoperative angiography in surgical planning of patients with complex skull base tumors involving intracranial vascular structures and highlights the unique neovascularization that often occurs as meningiomas parasitize the exracranial blood supply.