Cerebellar Astrocytomas

Cerebellar astrocytomas are tumors in the cerebellum, a region of the brain—near the base of the skull—that coordinates muscle movement and balance. At Columbia University Irving Medical Center/NewYork-Presbyterian Hospital, our neurosurgeons specialize in diagnosing and surgically treating cerebellar astrocytomas.

Like other astrocytomas of the brain and spinal cord, cerebellar astrocytomas develop from astrocytes.

The World Health Organization grades tumors on a scale of one to four. The grade indicates the speed at which a tumor grows and its ability to spread to nearby tissues. Most cerebellar astrocytomas (80 percent) are low grade tumors, meaning they are slow-growing and rarely spread. High grade astrocytomas in the cerebellum, although rare, grow quickly and can spread.


Symptoms vary and depend on tumor location and other characteristics.

As cerebellar astrocytomas grow, they can block the flow of cerebrospinal fluid (CSF), which bathes and protects the brain. The blockage may lead to hydrocephalus and in turn increase intracranial pressure.

Individuals who have elevated intracranial pressure may experience headaches, particularly in the morning; vomiting and/or nausea; and neck pain or stiffness. Having a headache when waking up in the morning is the most common symptom of cerebellar astrocytomas.

Individuals with cerebellar astrocytomas may also experience the following symptoms:

  • Torticollis
  • Ataxia
  • Macrocephaly: Particularly in infants and young children, hydrocephalus can cause the head to enlarge.
  • Nystagmus
  • Changes in personality or behavior (for example, developing anxiety or having mood swings)
  • Dizziness


A physician can identify the symptoms of a cerebellar astrocytoma during a physical examination and neurological examination. However, since the relevant symptoms are not specific to cerebellar astrocytomas, these examinations alone cannot provide a diagnosis, and imaging tests are necessary.

The imaging test of choice is magnetic resonance imaging (MRI). Using magnets, radio waves, and a computer, MRI produces highly detailed images of the brain that can show a tumor. If an individual cannot undergo MRI or MRI is not available, computed tomography (CT) scan is used instead. Using X-rays and a computer, a CT scan can produce an image of a tumor in the brain. For both of these imaging tests, a contrast agent (either injected as a dye or swallowed as a pill) is typically used to enhance the image of the tumor.

To confirm a diagnosis, a neurosurgeon may perform a biopsy. Depending on the location of the tumor and other factors, it may be necessary either to acquire a tissue sample during surgery to remove the tumor or to perform a stereotactic biopsy. During a stereotactic biopsy, a neurosurgeon drills a small hole in the skull. Using a computer and other technology, a neurosurgeon guides a needle through that opening and to the tumor in order to acquire a tissue sample. The stereotactic biopsy procedure is far less invasive than surgery to remove a tumor.

Risk Factors

As is the case for brain tumors in general, the cause of cerebellar astrocytomas is unclear.

Most cerebellar astrocytomas occur in children and young adults. They occur only rarely in infants and older adults.

Cerebellar astrocytomas are not inherited. However, certain inherited conditions, such as neurofibromatosis type 1 (NF1) are associated with increased risk of developing these tumors.


Treatment of cerebellar astrocytomas can vary and depends on the location of the tumor and severity of symptoms. Our neurosurgeons will evaluate an individual’s tumor and then create a treatment plan tailored for each individual.

In a typical surgery, a neurosurgeon will first perform a craniotomy and then remove as much of the tumor as possible. For most patients, particularly those with low grade tumors, this procedure alone cures the cerebellar astrocytoma. Removing the tumor also allows the CSF to flow normally, in turn alleviating symptoms for most patients who have been suffering from hydrocephalus.

For some patients, a neurosurgeon may also recommend radiation therapy, chemotherapy or both to treat any remaining tumor or to prevent the tumor from growing back.

If removing the tumor does not alleviate pressure, or if pressure inside the skull is too high to wait for a craniotomy, a neurosurgeon may perform a ventriculostomy. This procedure involves drilling a hole in the skull and inserting a catheter into one of the ventricles to drain fluid and relieve pressure.