Cavernous angiomas are vascular malformations consisting of small cavities filled with blood. In most cases, the lesions are well-defined. They are more or less spherical in shape and look like a "raspberry" to the naked eye. The size varies from a few millimeters to a few centimeters. Cavernous malformations are mainly found in the brain but they may also be located in the spinal cord and, more rarely, outside the central nervous system (retina, skin, peripheral nerves etc.). Cerebral cavernous malformations may be complicated by ICHs but of small volume because of very low blood flows through the malformations.
In 40% of cases, there is a venous malformation close to the cavernous malformation. It is often referred to as a "developmental venous anomaly" (DVA) and it produces no clinical symptom.
There are two types of cavernous angiomas:
- the sporadic type, usually as single lesion and with no familial context
- and the familial type that is clinically defined by the presence of multiple lesions and the existence of at least one relative who also has cavernous angiomas. To date, three genes have been found to be implicated in these hereditary forms.