The patient had a shunt placed for obstructive hydrocephalus. An endoscopic biopsy of the intraventricular and septal mass was performed which showed findings consistent with a cavernous angioma (Fig. 1). Intracranial vascular malformations are divided into four groups: (i) capillary telangiectasia, (ii) cavernous angioma, (iii) arteriovenous malformation, and (iv) venous malformation. Cavernous angiomas comprise 5% to 13% of all vascular malformations and occur in about 0.5% of the general population. Cerebral cavernous angiomas occur sporadically and in a familial form. Familial cavernous angiomas account for up to 54% of cerebral cavernous angiomas. The most frequent symptoms are seizures, gross intracranial hemorrhages, focal neurological deficits, and migraine-like headaches. The prospective annualized hemorrhage rate calculated on a per-patient basis is 1.6% to 3.1%. Intracranial cavernomas are commonly located in the supratentorial region, brain stem, basal ganglia, and cerebellar hemisphere. On the basis of MRI, four