Vascular Malformations Overview

Terminology

Without a uniform consensus, there is much confusion regarding the nomenclature of brain CVMs. They have variously been called angiomas, hemangiomas, developmental anomalies, malformations, and hamartomas. For example, venous vascular malformations have been termed venous angiomas, venous anomalies, venous malformations, and developmental venous anomalies. Cavernous malformations have been called cavernous angiomas, cavernous hemangiomas, and “cavernomas” in the literature.

Using accurate terminology when discussing brain vascular malformations is important. Two major groups of vascular anomalies are recognized: Vascular malformations and hemangiomas. All CVMs (“angiomas”) are malformative lesions. In contrast, “hemangiomas” are true proliferating, vasoformative neoplasms and, in the most recent WHO classification “Blue Book,” are included with the mesenchymal, nonmeningothelial tumors.

Hemangiomas are benign vascular neoplasms, not malformations, and can be capillary or cavernous. Most intracranial hemangiomas are found in the skull, meninges, and dural venous sinuses, whereas most vascular malformations occur in the brain parenchyma. Therefore, the term hemangioma should be reserved for vasoproliferative neoplasms and not used to describe vascular malformations. In this text, CVMs are included in this section; hemangiomas are considered as neoplasms and included elsewhere.