Intracranial aneurysms associated with other lesions, disorders or anatomic variations.

Intracranial aneurysms (IAs) can be related to or associated with some vascular anatomic variations, lesions, diseases, or systemic disorders in which a causative or predisposing factor(s) in aneurysm formation can be identified. This article includes flow-related, infectious, traumatic iatrogenic, and neoplastic aneurysms and aneurysms related to systemic disorders and drug abuse. In some conditions, IAs associated with other disorders are true aneurysms. Most of them, however, are false aneurysms. Characteristics and management of these unusual aneurysms are discussed.