Intra-mural propagation of a large cavernous internal cerebral artery aneurysm after parent artery sacrifice.

The mechanism of aneurysm growth after isolation from the circulation is not well known. We report a case of a woman who presented with mass effects of a large cavernous internal carotid artery (ICA) aneurysm. The parent vessel harboring the aneurysm was sacrificed but the aneurysm continued to enlarge with propagation of the disease along the vessel wall progressively extending to the middle cerebral artery (MCA) leading to ischemic stroke. This case provides imaging evidence of the role of mural inflammation in the development of certain aneurysms.