(May 2014). Cavernous hemangioma, also called cavernous angioma, or cavernoma (often when referring to presence in the brain), is a type of blood vessel malformation or hemangioma, where a collection of dilated blood vessels form a tumor.Because of this malformation, blood flow through the cavities, or caverns, is slow.May 2014). Cavernous hemangioma, also called cavernous angioma, or cavernoma (often when referring to presence in the brain), is a type of blood vessel malformation or hemangioma, where a collection of dilated blood vessels form a tumor.