Brain Tumors
Also known as: Supratentorial
tumors: astrocytomas, ependymomas
Infratentorial tumors: medulloblastomas, astrocytomas,
ependymomas
What
is it?
A brain tumor is an abnormal
growth of tissue in the brain. Brain
tumors rarely spread (metastasize) outside the
brain. You may hear doctors refer to brain tumors
as “benign” or “malignant.”
A benign tumor is non-cancerous and does
not spread beyond the area where it began.
However, benign tumors can sometimes become
malignant. Malignant
tumors contain cancerous cells or are located in
an area where they interfere with the brain’s
vital functions.
A malignant brain tumor can spread to and destroy tissue in
other parts of the brain.
Brain tumors are classified according to
their location in the brain and the type of cells
they begin as.
In children, brain tumors are described as
supratentorial (in the upper part of the brain,
the cerebrum) or infratentorial (in the lowest
part of the brain, the cerebellum).
More than one-half of all childhood tumors
occur in the lower part of the brain.
There are a variety of malignant
(cancerous) tumors that occur in children. They are typically
categorized by the organ where the tumor started. The approach to
treatment is fairly uniform.
- Identify the extent and
location of the mass
Involves a thorough health history, physical exam,
laboratory exams, and radiology studies (CT scans, MRI, Ultrasound)
- Biopsy or removal of the tumor
To identify the type of cell involved and whether it is cancerous or
not. The determination of
how to proceed is determined by the location and extent of
disease. The decision is made following input from the team of
professionals; (oncologist, surgeon, and others as needed) and discussion of risks and benefits with the
family.
- Determine plan of care
Determined by
pathology (type of cells) and the extent of disease(staging).
This happens quite rapidly and can
be a very difficult time for patients and their families. The
key to surviving the initial diagnosis process is getting answers
to your questions. Don't hesitate to ask any questions, your
understanding is essential.
Who
gets it?
Brain tumors are the second
most common type of tumor in children. They
account for almost 21% of tumors, and are a
leading cause of death in children younger than 15
years of age.
Most brain tumors develop by age 10.
The incidence is 2.2-2.5 cases per
100,000, with the peak being between birth and 10 years of age.
Brain tumors are slightly more common in boys.
What
causes it?
The exact cause of pediatric
brain tumors is unknown.
Some tumors have been linked to hereditary
syndromes, such as neurofibromatosis type I and
type II, tuberous sclerosis, and von Hippel-Landau
disease. While
studies have shown no clear environmental link,
radiation therapy can cause tumors to develop.
Patients with immunodeficiency diseases like
Wiskott-Aldrich syndrome or AIDS are also more
likely to develop these types of lymphomas.
What
are the symptoms?
Symptoms of brain tumors are
related to:
- Size and location of the tumor
- Pressure on surrounding
structures of the brain
- Increase in pressure within the
brain
- Child's age
An aggressive tumor will have more severe
symptoms, while a slow growing tumor may be harder
to detect. If
the tumor is blocking the pathway of the
cerebrospinal fluid (CSF), the child may show
signs of hydrocephalus (an enlargement of the
skull) and increased intracranial pressure (ICP).
Both cause headaches. Around 60% to 65% of
children with brain tumors will have headaches as
a major symptom. Pain is so severe that it can
awaken them from sleep, and is at its worst first
thing in the morning.
In most cases, headache is accompanied by
nausea and vomiting.
When ICP affects the brain stem, symptoms may include double
vision, slurred speech, and swallowing and
breathing disorders.
Seizures are a more likely symptom of
supratentorial tumors, those located in the upper
part of the brain, and occur more often in
adolescents.
Children with seizures caused by a brain
tumor may also have impaired speech, problems with
schoolwork, and personality disorders.
Supratentorial tumors can also cause
weakness or paralysis in the limbs on one side of
the body. Other
symptoms depend upon the specific location of the
tumor and can include excessive thirst and
urination (diabetes insipidus), growth disorders,
difficulties gazing upward, irritability,
lethargy, and failure to thrive.
Diagnosis
Brain tumor is diagnosed through a combination
of symptoms and evaluation of neurological
functions. Abnormal
head growth during a regular pediatric checkup can
indicate either hydrocephalus or brain tumor.
Almost all children with headache as a
symptom will also have neurological or
vision-related symptoms that can be found through
a physical examination.
Most brain tumors will show up through a
process called magnetic resonance imaging (MRI).
Through an MRI, the doctor can measure the tumor’s size and
see its exact location.
However, the child must lay completely
still during this scan.
A computed tomography (CT) scan can also be
used. Your
doctor may also recommend magnetic resonance
angiography, which can reveal vascular
malformations in the brain that might be mistaken
for a brain tumor.
After treatment for a malignant brain
tumor, your doctor may perform additional tests
such as a spinal tap, bone marrow analysis, or
bone scan to check whether the cancer has spread.
What is the Treatment
The treatment for brain tumor depends upon the
child’s age and the location and size of the
tumor. The
main treatment is surgery, but chemotherapy and
radiation may also be needed.
If your child has signs of increased
intracraneal pressure, but is stable, he or she
may be given the drug dexamethasone, which usually
decreases tumor swelling and can also reduce
cerebrospinal fluid (CSF) production within the
first day of treatment.
If your child has severe neurological
symptoms caused by a build-up of CSF, he or she
may need a shunt inserted into one of the cavities
in the brain to drain the CSF until the tumor can
be reduced through surgery.
A shunt includes a valve that opens to allow fluid to leave
the brain and drain into the abdomen when pressure
becomes too high.
Some patients need a permanent shunt even
after surgery.
The goal of surgery is the removal of as
much of the tumor as possible.
Depending upon the size and location of the tumor, the child
may have long-term complications that affect
cognitive functions, vision, and coordination.
Surgery may not be possible in some cases
where the tumor involves the brain stem. Careful
radiation to the tumor and any other affected
areas damages the cells’ DNA strands and make it
difficult for the cells to continue dividing.
However, because radiation has potential
long-term side effects, young children and infants
are more likely to be treated with low-intensity
chemotherapy.
With chemotherapy, cancer-fighting drugs
are given intravenously.
Side effects, such as nausea and vomiting
are treated with drugs such as ondansetron,
granisetron, metoclopramide, antihistamines,
chlorpromazine, and benzodiazepines.
Most
childhood cancer centers belong to the Children's
Oncology Group. They are responsible for the
development of protocols or clinical trials
(treatment plans) specifically for children,
adolescents and young adults.
Self-care
tips
If your child has had surgery
to remove a brain tumor, it’s important to
minimize the chances of infection by washing your
hands frequently when caring for your child, avoid
people who have colds or other viral illnesses,
and call your doctor immediately if your child has
fever or persistent severe headache.
This information has been designed as a comprehensive and quick reference
guide written by our health care reviewers. The health information written
by our authors is intended to be a supplement to the care provided by your
physician. It is not intended nor implied to be a substitute for
professional medical advice.
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