[A case with giant aneurysm of distal portion of the posterior inferior cerebellar artery (author's transl)].

A case of a giant aneurysm of the distal posterior inferior cerebellar artery has been presented, in which the preoperative sympotoms were those of a space occupying lesion of the posterior fossa. CT scan revealed a round mass in the cerebellum. The wall of this round mass was not enhanced after an intravenous administration of iodine. At operation we found a large saccular aneurysm, about 3 cm in diameter, arising from the distal portion of the left posterior inferior cerebellar artery. By needle decompression and dissection around the aneurysm, we were able to place a Heifetz clip across the neck. After exicision, the aneurysm was found to contain a large thrombus.