Rare presentation of intracranial vascular blowout after tumor resection and radiation therapy.

A middle-aged patient presented with a rapidly growing right dural-based extra-axial posterior clinoid mass extending to the right cavernous sinus that was surgically resected. Histological examination showed solid growth of primitive neuroectodermal tumor arising from the third nerve. Following surgical resection, the patient was further managed by radiation and chemotherapy. Two years later the patient developed new intracranial hemorrhage in the area adjacent to the previous surgical cavity. A cerebral angiogram showed contrast extravasation at the junction of the posterior communicating artery (Pcom) and the right posterior cerebral artery (PCA), with an expanding pseudoaneurysm. This was managed with N-butyl cyanoacrylate embolization. Autopsy showed microscopic recurrence of tumor into the PCA/PCom region with invasion of the wall of the Pcom. This case report illustrates the concept of vascular blowout in intracranial cerebral vasculature. It appears that, in the presence of risk factors that contribute to weakening of vessel walls (surgery, radiation, tumor recurrence), a blowout can occur intracranially.