Current Evidence Cavernous malformations (CMs), also known as cavernous angiomas or cavernomas, are compact lesions comprised of sinusoidal vascular channels lined by a single layer of endothelium that lacks the full complement of mature vessel wall components Between the vascular channels in the core of the lesion, there is loose connective tissue stroma without intervening brain parenchyma The prevalence of CMs has been estimated to be between 0.4% and 0.9% of the population and 8% and 15% of all vascular malformations They present with headache, seizure, focal neurologic deficit, or as an incidental radiographic finding The majority of CMs are located supratentorially, typically in the white matter of the cerebral hemispheres The infratentorial CMs are located in the cerebellum, pons, midbrain, and medulla Less frequent locations of CMs are the lateral and third ventricles, cranial nerves, and optic chiasm Acute hemorrhage from a chiasmal CM is a rare cause of permanent visual loss Of the extracerebral locations, the cavernous sinus, the orbits, and the spinal cord are the most common Diagnostic Imaging CT is more sensitive at detecting CMs, but its specificity is low since most appear simply as high-density lesions (acute hemorrhage) with little or no contrast enhancement This is in contrast to the high sensitivity and specificity of MRI for CMs The MRI appearance of CMs has been categorized into four types: a hyperintense core on T1and T2-weighted images representing subacute hemorrhage (Type I); a “classic” picture of mixed-signal, reticulated core surrounded by a lowsignal rim (Type II); an iso- or hypointense lesion on T1 and markedly hypointense lesion with hypointense rim on T2, which corresponds to chronic hemorrhage (Type III); and punctate, poorly visualized hypointense foci, which can be visualized only on gradient echo MRI, representing tiny CM or telangiectasia (Type IV) Management With most asymptomatic CMs, particularly when the diagnosis is relatively clear by MRI characteristics, the right approach for the patient is conservative management with close follow-up Type I and II CMs are composed of acute or subacute hemorrhage and are more likely to rebleed and may warrant closer follow-up In contrast to a bleeding episode from an AVM, a bleeding episode from a CM is rarely life threatening However, there is more controversy with symptomatic CMs which hemorrhage in deep, difficult-to-access surgical locations