Angiographical Arteriovenous Malformation Histologically Verified as Venous Angioma: Report of Two Cases

In the classification of cerebral vascular malformations, a mixed or transitional type of malformation has come to be recognized as distinct from the classical assortment, that is, AVM, capillary telangiectasia, cavernous angioma and venous angioma. We recently experienced two cases in which findings of cerebral angiography indicated arteriovenous malformation; however, histological examination of the lesion showed a typical venous angioma. We could not find a report of a similar case in the literature. We consider that these two cases belong to a transitional or mixed type of cerebral vascular malformation composed of arteriovenous malformation and venous angioma.