Angiodysplasia: New Look at an Old Conundrum

Angiodysplasia is a unifying concept and designation for all developmental vascular anomalies currently known in the medical literature as angiomatosis, arteriovenous malformation, congenital arteriovenous fistula, congenital hemangioma or lymphangiomatosis, telangiectasia, vascular hamartoma, and all those clinical disorders identified by eponyms, such as Klippel-Tranaunay syndrome and Rendu-Osler-Weber syndrome. A new classification is proposed to catalog the histomorphologic spectrum of angiodysplasia likely to be found in each individual case with the caveat that virtually all angiodysplastic lesions will have mixed histomorphology although one type may predominate. Examples of the most commonly encountered angiodysplastic lesions are described and illustrated in this review.