Discussion Author: Matthew J Hoffman There are four major types
of vascular malformation: Â» arteriovenous malformation Â»
cavernous malformation (cavernous hemangioma) Â» capillary
telangectasia Â» developmental venous anomaly (venous angioma)
They are composed of radially arranged, dilated anomalous veins
that converge into a "collector vein" - an enlarged
transcortical or subependymal draining vein. Microscopically
they consist of dilated, thin walled venous channels separated
by normal brain tissue. The precise etiology is unknown but they
likely represent extreme anatomic variants and not true vascular
malformations. They are located in the deep cerebral or
cerebellar white matter, most often near the margin of an
adjacent ventricle. The most common site is adjacent to the
frontal horn of the lateral ventricle. They can occur at any age
and often are asymptomatic and therefore may be incidental
findings on imaging studies. They are the most common vascular
â€śmalformationâ€ť found at autopsy. Most are so