What is pilocytic astrocytoma?
Pilocytic astrocytoma (PA) is a slow-growing type of brain tumor. The term “astro” or
"astrocyte" comes from the name of the star-shaped cells from which these tumors
develop. Astrocytes are a major type of non-nerve cells in the central nervous system
(CNS). The CNS is made up of the brain and spinal cord. Many different types of brain
tumors grow from astrocytes. But PA tumors tend to be among the slowest growing. They
tend to be found mostly in children and teens.
tumor is an abnormal growth of cells. Healthcare providers who specialize in examining
cells under a microscope are called pathologists. They can grade the tumor, on a scale
from I to IV, based on how abnormal the cells look and how fast the tumor is likely to
grow and invade other tissues. The cells from a grade I tumor look almost normal and
grow slowly. A grade IV tumor grows very quickly.
tumors are grade I and tend to grow very slowly. They usually have well-defined borders.
They rarely invade nearby tissues. The cells look almost normal under a microscope. Some
healthcare providers consider them to be benign or not cancer because of these
PA is a primary CNS tumor. That means that it starts in the brain or spinal cord rather than somewhere else in the body and spreading to the brain. PA most often happens in children and teens, but it can also affect adults.
tumor in the brain may cause problems by pressing against brain tissue. The standard
treatment for PA is surgery to remove the tumor, when possible. If the tumor is removed,
the outlook is usually good.
What causes PA?
Researchers don’t yet know what causes PA tumors. Healthcare providers also don’t have
a clear idea about the risk factors for these tumors. Research has suggested links
between some genetic conditions and these tumors.
What are the symptoms of PA?
symptoms of PA depend on where and how big the tumor is. It may not cause symptoms until
it's big enough to press on nearby brain tissue and cause problems.
PA tumors often grow in the
cerebellum, near the back of the brain. The cerebellum controls balance and
coordination. PA tumors sometimes affect the optic nerve and vision. A PA tumor may also
block the normal flow of cerebrospinal fluid (CSF). CSF normally bathes and cushions the
brain and spinal cord. As CSF builds up, it causes increased pressure on the brain
(intracranial pressure). This may cause:
How is PA diagnosed?
Healthcare providers usually ask about your personal and family medical history, recent
symptoms, and past health history. You'll need a physical exam and a nervous system
exam. For this, your provider will check your coordination and reflexes. Your provider
may ask you to do simple things like walk, touch your finger to your nose, or hold your
hands out. Your provider might examine your eyes with a light. If a brain tumor is
suspected, imaging scans of your brain, often with a contrast media, will be needed. You
may need certain tests and procedures, such as:
MRIs use radio waves, magnets, and a computer to make detailed images of the inside
of your body. For this test, you lie still on a table as it passes through a long,
tube-like scanner. If you're not comfortable in small spaces, you may be given
medicine to help you relax before the test. A contrast dye may be injected into your
blood for this test. It helps outline the structures in your head so they show up
more clearly on the scans.
CT scan uses a series of X-rays and a computer to create detailed images of the
inside of your body. For this test, you lie still on a table as it slowly slides
through the center of the ring-shaped CT scanner. The scanner directs a beam of
X-rays at your body. A CT scan is painless. A dye might be put into your blood to
help get clearer images.
A biopsy is the only sure way to know what kind of tumor you have. In a biopsy, a
tiny piece of the tumor is taken out and tested in a lab.
may first see your primary healthcare provider and then get a referral to a:
Neurologist, a specialist in diagnosing and treating diseases of the brain
and spinal cord
Neurosurgeon, a specialist who does brain or spinal cord surgery
Neuro-oncologist, a specialist in brain and spinal cord cancers
How is PA treated?
standard treatment for PA tumors is surgery to remove them. If the tumor is in a spot
where it can’t be fully removed, radiation therapy and chemotherapy may be used.
Sometimes radiation therapy is used after surgery. But because PA tumors grow very
slowly, your healthcare provider may want to “watch” first to see if the tumor comes
back. This is because the risks of the radiation therapy may outweigh the risk of the PA
will talk with your medical team about the best treatment plan for you. You'll likely
need ongoing follow-up with your healthcare provider. This may include repeated imaging
tests to check for signs that the tumor has come back. It's very important to keep
follow-up appointments so that your medical team can watch for any changes.
some cases, the PA tumor may block drainage of the CSF from your brain. This, causes CSF
to build up in the brain. If this happens, you may need surgery to put a tube (called a
shunt) in place to drain excess CSF. After the tumor is removed, CSF can drain the way
it should, and this problem goes away.
What are possible complications of
Overall, the outcome is good for most people with PA tumors. Rarely, they might come
back after treatment.
Key points about pilocytic
PA is a
type of brain tumor. It starts in the star-shaped astrocyte cells in your brain.
These tumors are generally very slow growing.
most often occur in children and teens, but sometimes happen in adults.
tumors are often benign because they seldom invade nearby tissues.
usual treatment for PA is surgery to remove the tumor, if possible.
People with these tumors tend to have a good outcome after treatment.
very important to follow up with your medical team to continue to watch for any
changes after treatment.
Tips to help you get the most from a visit to your healthcare provider:
Know the reason for your visit and what you want to happen.
Before your visit, write down questions you want answered.
someone with you to help you ask questions and remember the answers. Taking notes can
At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.
why a new medicine or treatment is prescribed, and how it will help you. Also know
what side effects you should watch for.
Ask if your condition can be treated in other ways.
Know why a test or procedure is recommended and what the results could mean.
what to expect if you don't take the medicine or have the test or procedure.
If you have a follow-up appointment, write down the date, time, and purpose for that visit.
Know how you can contact your provider if you have questions.