Updated June 26, 2014.

A cavernous malformation is a small nest of abnormal blood vessels located inside the tissue of a given body organ, such as bone, intestine or brain. When cavernous malformations occur in the brain, however, they can be particularly problematic. In general, cavernous malformations consist of thin-walled veins, which lack major incoming arteries, and are fully separate from the tissues where they live.

As such, cavernous malformations tend to be smaller and less dangerous than the more prominent arteriovenous malformations.

Do Cavernous Malformations Cause Bleeding?

In spite of being small, cavernous malformations have a significant tendency to cause bleeding in the brain. The bleeding, however, is typically small, self-contained and relatively minor. In a fraction of the cases, however, bleeding is unusually large and cause a life-threatening hemorrhagic stroke. Once a cavernous malformation bleeds, it carries a high risk of re-bleeding, especially within the following 2 to 3 years.

How Are Cavernous Malformations Diagnosed?

Typically, cavernous malformations are diagnosed by MRI. They have the appearance of a small mass with blood deposits around it. Sometimes, however, it is impossible to differentiate a cavernous malformation from small tumors or infections, so your doctor may choose to perform further tests to arrive at a final diagnosis.

Who Gets Cavernous Malformations?

Cavernous malformations occur in approximately 0.5% of the population.

They can be found in all age groups, but they are usually discovered between the ages of 10 and 30. Some cases are familial, meaning that they occur in multiple members of the same family. This suggests that in these cases, there may be an underling genetic cause.

What Are the Symptoms?

Typically, cavernous malformations do not cause any symptoms, but after they bleed, they can cause seizures, headaches and other stroke symptoms.

What Is the Treatment?

Some symptoms, such as seizures, can often be controlled with medicines. In cases in which medicines are not sufficient, however, a surgery to remove the cavernous malformation from the brain can be performed. When successful, this surgery can completely cure seizures in many patients. If significant bleeding has already occurred, the surgery can prevent further bleeding episodes.
Another modality of treatment available for cavernous malformations is radiation therapy. Since there are some potentially dangerous long-term side effects of this therapy, though, this is not typically performed unless surgery is not a possibility.

_{Source: Bradley G Walter, Daroff B Robert, Fenichel M Gerald, Jancovic, Joseph Neurology in clinical practice, principles of diagnosis and management. Fourth Edition, Philadelphia Elsevier, 2004.}

Robinson JR, Awad IA, Little JR.: Natural history of the cavernous angioma. J Neurosurg 75:709–714, 1991.