Arteriovenous malformations of the intestine.

Arteriovenous malforamtions of the intestine are recognized as an uncommon cause of chronic gastrointestinal bleeding. In previous reports, the role of selective mesenteric angiography in the localization of the lesion has been emphasized; with confirmation by in vitro injection of radioopaque dye into the resected specimen. The histologic appearances of arteriovenous malformations are well recognized, although terminology is still confused. In this report, two distinct entities of small vessel malformation are described and the terms submucosal endothelial angiodysplasia and submucosal fibromuscular angiodysplasia are offered.