Arteriovenous malformation of the brain -- histological study and micrometric measurement of abnormal vessels.

An autopsy case of arteriovenous malformation (AVM) of the brain in a 29-year-old housewife was reported. Several important and characteristic findings were obtained by detailed histological examination and micrometric measurement of abnormal vessels composing the nidus of the AVM. Structural imperfectness and immaturity of their vascular wall suggested that the AVM is a histoembryogenic maldevelopment. Prominent dilatation in calibre, hypertrophy of muscular layer, hyalinization, and abnormal increasing of elastic fibers were interpreted as the result of changed cerebral hemodynamics caused by an arteriovenous fistulous communication.