Thrombosis, growth, recanalization, and rupture of a saccular, non-giant cerebral aneurysm.

A partly thrombosed, saccular, non-giant left internal carotid artery aneurysm was discovered during an evaluation for headaches in a 75-year-old woman. A mirror-image aneurysm of the right internal carotid artery was also found. During the course of about a year, the left-sided aneurysm thrombosed, grew to giant proportions, recanalized, and ruptured. During this same time, the right-sided aneurysm remained unchanged in size or shape. Even a saccular, non-giant, thrombosed aneurysm can be potentially dangerous. Such an aneurysm requires careful monitoring. If clinically appropriate, aneurysm treatment is indicated.