Hemangioblastoma of the Brain
Hemangioblastomas are rare tumors that occur in blood vessels of the brain and spinal cord. They may appear anywhere in the brain but are most often found in the cerebellum and the brainstem in the lower back section of the skull called the posterior cranial fossa. It is estimated that hemangioblastomas make up 8 percent to 12 percent of the tumors in this region but only 1 percent to 2.5 percent of all brain tumors.
Although hemangioblastomas are benign (noncancerous) tumors, if they are located adjacent to a vital structure they can pose a serious threat and be difficult to treat. They attach to the pia mater, the innermost layer of the membranes surrounding the brain and spinal cord (the meninges), deriving their blood supply from this source.
Because these tumors involve blood vessels, they pose a threat of rupturing, and because they tend to grow slowly, they may go undetected for months or years. A previously undiagnosed hemangioblastoma sometimes ruptures – causing bleeding into the brain –before any other symptoms occur.
Rarely occurring in children, hemangioblastomas are about twice as common in men as in women and are usually diagnosed between ages 20 and 40.
Causes and Risk Factors
While there is no known cause for most hemangioblastomas, about 25 percent of the tumors are linked to a genetic syndrome called von Hippel-Lindau disease, a condition that also includes vascular abnormalities in the retinas and an increased risk of developing cancers in various organs, such as the kidneys, adrenal glands and pancreas.
Hemangioblastomas associated with von Hippel-Lindau disease often recur after surgical removal.
Like hemangioblastomas themselves, symptoms tend to increase gradually over a long period of time. Individual symptoms vary greatly, depending on which area of the brain is compromised.
Because hemangioblastomas often affect the cerebellum, which is responsible for movement, balance, equilibrium and muscle tone, many patients will have difficulty walking, standing or moving in a coordinated manner.
A tumor in the brainstem can have far-reaching consequences because this structure carries nerve signals from the brain to the spinal cord for distribution to the body, and it provides nerves for movement and sensations in the face and neck.
If a growing tumor presses against cerebrospinal fluid channels, obstruction can occur, causing intracranial swelling and pressure (hydrocephalus) that can have many serious and even life-threatening consequences without treatment. In these cases, a surgical procedure may be performed to insert a shunt that drains fluid out of the cranium and into the abdominal cavity, where it is harmlessly absorbed.
Symptoms of a ruptured hemangioblastoma are often sudden and dramatic, as pressure within the closed environment of the cranium compresses brain structures. Emergency treatment is required.
Because hemangioblastomas may occur spontaneously or be related to a genetic disorder, Cedars-Sinai doctors will conduct a very thorough series of examinations to determine if any other tumors or conditions exist. In addition to performing a complete physical exam and personal and family history, they will typically order a variety of imaging studies of the brain, spinal cord and body.
These may include ultrasound studies and computed tomography (CT) images, but magnetic resonance imaging (MRI) is considered the best choice for diagnosing a hemangioblastoma. Angiography may be used to view the details of the blood vessel or vessels involved, which can be valuable in treatment planning and surgery.
Occasionally, a hemangioblastoma that is not causing symptoms may be monitored over time, especially if the patient is not healthy enough to undergo an operation and the tumor is not causing serious problems. A patient taking blood-thinning medication, for example, may not be a good surgical candidate because of the high risk of hemorrhage during surgery.
In most cases, surgical removal of the tumor is considered the first choice for treatment, but Gamma Knife radiosurgery has recently become an appealing alternative to open surgery in certain cases.
Surgical approaches vary by the tumor’s location and individual characteristics. Because the tumors typically occur in the lower back part of the cranium, surgeons often remove a small section of bone in this area and use microsurgical techniques to sever the blood vessels feeding the tumor and remove it. While about half of hemangioblastomas are solid tumors, others contain a fluid-filled cyst that may be drained, making the tumor easier to define and remove.
Large hemangioblastomas may require two procedures – one to “embolize” (block) the blood supply to the tumor and the second to remove the tumor. Embolization is usually performed through a minimally invasive, catheter-based approach in Cedars-Sinai’s advanced 3D Neurovascular Imaging Suite. According to recent studies, the ability to stop the blood flow to a hemangioblastoma improves surgical outcomes.
Hemangioblastomas associated with the rare von Hippel-Lindau disease frequently recur after surgical removal. Radiosurgery, especially with the Gamma Knife, may be a better option in many cases, and chemotherapy that targets tumor-feeding blood vessel growth may also be prescribed.Back to top
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