The authors report the coexistence of a cerebral aneurysm and a cerebral venous angioma, which is very rare, in a 24-year-old female admitted because of sudden onset of severe headache and convulsive seizures. There were no abnormal neurological findings other than meningeal irritation. Plain computed tomography (CT) showed an intraventricular hematoma and contrast-enhanced CT demonstrated a umbrella-shaped region of high density in the right parietal lobe. Right serial carotid angiography disclosed slight enlargement of the branches of the middle cerebral artery and, in the late arterial to capillary phase, blushing was evident in the right parietal lobe. The small medullary veins converged into a single large vein that penetrated the brain and drained into the superior sagittal sinus in the venous phase. A vertebral angiogram demonstrated a saccular-appearing aneurysm in the plexal segment of the right posterolateral choroidal artery, which was joined distally to the venous angioma. These angiographic findings resemble those of peripheral artery aneurysms associated with moyamoya disease. It is possible that the aneurysm arose through hemodynamic stress and ruptured into the ventricle. Numerous types of vascular anomalies have been reported in the literature. This case further illustrates that there are several transitional types to be included in the proposed classifications, such as Russell and Rubinstein's.
