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Cavernous Malformation

Cavernous Malformation Overview

A cavernous malformation is a cluster of dilated blood vessels (capillaries) with an enlarged and irregular structure. The walls of these capillaries are thinner than normal, have loose junctions between cells, and are prone to leaking.

These abnormalities can occur anywhere in the body, but they are most likely to produce symptoms when they form in the brain or spinal cord. They can cause neurological symptoms when they bleed into the brain (hemorrhage).

a cavernous malformation in the brain stem
This illustration shows the normal brain stem on the left and a cavernous malformation in the brain stem on the right. In the image on the right, the cavernous malformation is displacing the nerves of the spinothalamic tract. These nerves are responsible for relaying signals for temperature, pain, and touch from the body to the brain.

Cavernous Malformation Synonyms

There are several other terms that describe a cavernous malformation, including:

  • Cerebral cavernous malformation (CCM)
  • Cavernoma
  • Cavernous angioma
  • Cavernous hemangioma

Cavernous Malformation Symptoms

When a cavernous malformation leaks, bleeding can be slow and intermittent or rapid, causing sudden symptom onset. Most people who develop neurological deficits after a hemorrhage improve dramatically over time. However, repeated hemorrhages may result in permanent neurological problems.

Symptoms of a cavernous malformation may include:

  • Seizures
  • Headaches
  • Bleeding in the brain (hemorrhage)
  • Hearing or vision changes
  • Weakness, numbness, or paralysis
  • Memory deficits
  • Speech impairment
  • Unsteadiness

Cavernous Malformation Treatments

If you are diagnosed but not experiencing symptoms, your doctor may recommend observing the malformation over time with regular MRI scans.

Medications, such as anti-epileptic drugs, may be prescribed to control your seizures or other symptoms.

If your symptoms are not responding to medication or there is repeated bleeding in the brain, surgical removal may be recommended.

a cavernous malformation in the brain stem
This illustration shows a cavernous malformation in the brain stem and the best path, denoted by a blue line, for the neurosurgeon to access and remove it. The cavernous malformation is the purple-colored, berry-like structure in the lower right portion of the brain stem.

Additional Information

How common are cavernous malformations?

About one person in every 100 to 200 people has a cav mal, but about 25 percent of people affected never have symptoms.

Who gets cavernous malformations?

These lesions can affect children and adults. Most people who have symptoms are between 20 and 50 years old.

Most occur without any single identifiable cause, but in some cases they can be inherited genetically from your mother or father.

How are cavernous malformations diagnosed?

Your doctor may be able to diagnose you using an MRI alone because of the unique appearance of these malformations. Other possible tests that your doctor might order include:

  • CT scan
  • Angiography
  • Electroencephalogram
  • Blood tests
  • Genetic testing
mri showing a cavernous malformation in the brain. the red arrows point to the cavernous malformation
An MRI showing a cavernous malformation in the brain denoted by the red arrows.

Are cavernous malformations life-threatening?

These lesions usually are not life-threatening, but repeated bleeds may cause permanent neurological deficits. Malformations in sensitive tissue like the brain stem and thalamus can be extremely disabling if they bleed.

Do cavernous malformations go away?

These malformations do not go away without surgical removal. However, they may go dormant and stop bleeding. It is difficult to predict which  will bleed again and when.

Is a cavernous malformation a tumor?

These lesions are better described as abnormally formed blood vessels. They are not tumors in the sense of multiplying cells and growing tissue. They do not spread to other parts of the body and infiltrate organs like cancerous tumors.

Are cavernous malformations hereditary?

Most of these malformations occur spontaneously, meaning there is no known family history of the disease. However, 15 percent are caused by inherited genetic mutations.

Group 49
About 25 percent of people affected never have symptoms.

Surgical Videos

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Medically Reviewed by Michael T. Lawton, MD on February 18, 2021