Spontaneous disappearance of an aneurysmal malformation of the vein of Galen.

We describe spontaneous disappearance of an aneurysmal malformation of the vein of Galen (AMG), an anomaly that occurs most often in children, with a high mortality due to the accompanying severe cardiac failure. Spontaneous thrombosis of an AMG is rare. In this case, the AMG has been closed for about 5 years, without radiological evidence of thrombosis, and no active treatment. Proposed mechanisms of spontaneous thrombosis include slow flow shunts and severe obstruction of the venous outflow. However, in this case, the disappearance of the AMG without evidence of thrombosis indicates a different mechanisms, namely, obstruction of the feeding artery.