National Organization for Rare Disorders, Inc.
It is possible that the main title of the report Cavernous Malformation is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.
Vascular malformations or angiomas are localized collections of blood vessels that are abnormal in structure or number, lead to altered blood flow, and are not cancerous (nonneoplastic). Most vascular malformations are present at birth (congenital) and are suspected to arise between three and eight weeks of gestation, but the specific defect in embryogenesis has not yet been identified for each type of malformation. Some vascular malformations are not congenital, but caused by trauma, radiation, or other injury to the spinal cord. They are typically classified by size, location, and type of change, with the four most common being capillary telangiectasias, cavernous malformations, venous malformations, and arteriovenous malformations. Vascular malformations are sporadic and solitary in the majority of affected persons, however documented cases of autosomal dominant forms exist as well.
Cavernous malformations are dilated blood vessels that are characterized by multiple distended "caverns" of blood that flow very slowly. The blood filled vascular spaces are surrounded by blood vessel walls that do not have enough smooth muscle and stretchable material (elastin), so they are not strong and get distended. Cavernous malformations can be located anywhere in the body, including the liver, rectum, kidney, eyes, nerves, spinal cord and brain. Brain and spinal cord (cerebral) malformations will be focused on here, as they have the potential for serious symptoms.
Cerebral cavernous malformations (CCMs) are usually located in the white matter (cortex) of the brain. They are rarely located in the brainstem or hypothalamus, though this may be more common in children than adults. Locations in the spinal cord are more common in the adult population than in children. Cerebral cavernous malformations do not have brain tissue within the malformation like other lesions such as arteriovenous malformations, and they are usually do not have defined borders (are not encapsulated).
Cerebral cavernous malformations are dynamic, changing in size and number over time. They can range from 0.1 to 9 cm and usually reach a larger size in children than adults (who usually have cavernous malformations only 2-3 cm in size). There is no correlation between size and risk of bleeding or long-term symptoms of brain damage (neurological deficits). Very small amounts of bleeding (microhemorrhages) can cause the development of new vessels, but they usually do not cause physical symptoms. These microhemorrhages show up as black dots on an MRI and contribute to a patient's prognosis and ability to function.
According to several studies, cerebral cavernous malformations are present in about 0.5% of the general population, and they account for 8-15% of all brain and spinal vascular malformations. The prevalence of cavernous malformations in children is estimated to be between 0.37 and 0.53% (up to 1 in 200 children have a CCM, whether symptomatic or asymptomatic), and approximately 25% of all diagnosed cavernous malformations are found in children. Before eighteen years of age, peak ages of incidence have been found to be 0-2 years (26.8% of children with CCMs) and 13-16 (35.7%). It is unclear why they are distributed in this manner.
Other malformations can be present in combination with CCMs, such as small areas where the capillaries or veins do not form correctly (capillary telangiectasias or venous malformations), and this association occurs 8-44% of the time. In fact, some investigators think that some cavernous malformations come from capillary telangiectasias originally. These combinations are more common in children than in adults. When an association of more than one malformation exists (such as a CCM and venous malformation) in the same person, hemorrhage is more common.
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