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Childhood medulloblastoma is a disease in which benign (noncancer) or
malignant (cancer) cells form in the tissues of the brain.
Childhood medulloblastoma
(tumor)
usually forms in the cerebellum,
which is at the lower back of the brain. The cerebellum is the part of the brain
that controls movement, balance, and posture. Childhood medulloblastoma may also
be called primitive neuroectodermal tumor (PNET).
About 1 out of 5 childhood brain tumors are medulloblastomas. Although cancer
is rare in children, brain tumors are the most common type of childhood cancer
other than leukemia
and lymphoma.
Brain tumors can occur in both children and adults; however, treatment for
children may be different than treatment for adults.
The cause of most childhood brain tumors is unknown.
The signs of childhood medulloblastoma vary and often depend on the
child's age and where the tumor is located.
These symptoms
may be caused by a medulloblastoma or other conditions. A doctor should be
consulted if any of the following problems occur:
- Loss of balance, difficulty walking, worsening handwriting, or
slow speech.
- Morning headache or headache that goes away after vomiting.
- Nausea and vomiting.
- Unusual sleepiness or change in energy level.
- Change in personality or behavior.
- Unexplained weight loss or weight gain.
Tests that examine the brain and spinal cord are used to detect (find)
childhood medulloblastoma.
The following tests and procedures may be used:
- CT
scan (CAT scan): A procedure that makes a series of detailed pictures of
areas inside the body, taken from different angles. The pictures are made by
a computer linked to an x-ray
machine. A dye may be injected into a vein or swallowed to help the organs
or tissues show up more clearly. This procedure is also called computed
tomography, computerized tomography, or computerized axial tomography.
- MRI
(magnetic resonance imaging): A procedure that uses a magnet, radio waves,
and a computer to make a series of detailed pictures of areas inside the
brain and spinal cord. A substance called gadolinium is injected into the
patient through a vein. The gadolinium collects around the cancer cells so
they show up brighter in the picture. This procedure is also called nuclear
magnetic resonance imaging (NMRI).
Childhood medulloblastoma is diagnosed and removed in surgery.
If a brain tumor is suspected, a biopsy
is done by removing part of the skull and using a needle to remove a sample of
the tumor tissue.
A pathologist
views the tissue under a microscope to look for cancer cells. If cancer cells
are found, the doctor will remove as much tumor as possible during the same surgery.
Certain factors affect treatment options and prognosis (chance of
recovery).
The treatment options and prognosis
(chance of recovery) depend on the age of the child when the tumor is found, the
location of the tumor, the amount of tumor remaining after surgery, and whether
the cancer has spread to other parts of the central
nervous system (brain and spinal cord), or to other parts of the body, such
as the bones.
After childhood medulloblastoma has been diagnosed, tests are done to find
out if there is tumor remaining or if cancer cells have spread.
The extent or spread of cancer
is usually described as stages.
For childhood medulloblastoma,
risk groups are used instead of stages. Risk groups are described by the amount
of remaining tumor
or spread of cancer cells
within the central
nervous system (brain and spinal cord) or to other parts of the body. It is
important to know the risk group in order to plan the best treatment. The
following tests and procedures may be used to determine the risk group:
- MRI
(magnetic resonance imaging): A procedure that uses a magnet, radio waves,
and a computer to make a series of detailed pictures of areas inside the
brain and spinal cord. A substance called gadolinium is injected into the
patient through a vein. The gadolinium collects around the cancer cells so
they show up brighter in the picture. This procedure is also called nuclear
magnetic resonance imaging (NMRI).
- Lumbar
puncture: A procedure used to collect cerebrospinal
fluid from the spinal column. This is done by placing a needle into the
spinal column. A pathologist
views the fluid under a microscope to look for cancer cells. This procedure
is also called an LP or spinal tap.
- Bone
marrow biopsy: The removal of a small piece of bone and bone
marrow by inserting a needle into the hipbone or breastbone. A
pathologist views the samples under a microscope to look for abnormal cells.
- Bone
scan: A procedure to detect if there are rapidly dividing cells, such as
cancer cells, in the bone. A very small amount of radioactive
material is injected into a vein and travels through the blood stream. The
radioactive material collects in the bones and is detected by a scanner.
The following risk categories are used for childhood medulloblastoma:
Average risk
Childhood medulloblastoma is called an average risk if all of the following
are true:
- The child is older than 3 years of age.
- The tumor is at the very back of the brain.
- All of the tumor was removed by surgery
or there was a very small amount remaining.
- The cancer has not spread to other parts of the body.
Poor risk
Childhood medulloblastoma is called a poor risk if any of the following are
true:
- The child is younger than 3 years of age.
- The tumor is not at the very back of the brain.
- Some of the tumor was not removed by surgery.
- The cancer has spread to other parts of the body.
In general, cancer is more likely to recur
(come back) in patients in the poor risk group.
Recurrent Childhood Medulloblastoma
Recurrent
childhood medulloblastoma
is a tumor
that has recurred (come back) after it has been treated. Childhood
medulloblastoma often recurs. A tumor may come back many years later at the same
place or a different place in the brain. It can also come back in other parts of
the body such as the spinal cord.
There are different types of treatment for children with childhood
medulloblastoma.
Different types of treatment are available for children with childhood medulloblastoma.
Some treatments are standard (the currently used treatment), and some are being
tested in clinical
trials. A treatment clinical trial is a research study meant to help improve
current treatments or obtain information on new treatments for patients with cancer.
When clinical trials show that a new treatment is better than the "standard"
treatment, the new treatment may become the standard treatment.
Because cancer in children is rare, taking part in a clinical trial should be
considered. Clinical trials are taking place in many parts of the country.
Information about ongoing clinical trials is available from the NCI
Cancer.gov Web site 33.
Choosing the most appropriate cancer treatment is a decision that ideally
involves the patient, family, and health care team.
Children with medulloblastoma should have their treatment planned by a
team of doctors with expertise in treating childhood brain tumors.
Your child's treatment will be overseen by a pediatric oncologist,
a doctor who specializes in treating children with cancer. The pediatric
oncologist may refer you to other pediatric doctors who have experience and
expertise in treating children with brain tumors
and who specialize in certain areas of medicine. These may include the following
specialists:
- Neurosurgeon.
- Neurologist.
- Neuropathologist.
- Neuroradiologist.
- Rehabilitation
specialist.
- Radiation
oncologist.
- Medical
oncologist.
- Endocrinologist.
- Psychologist.
Four types of standard treatment are used:
Surgery
Surgery
is used to diagnose and treat childhood medulloblastoma.
Radiation therapy
Radiation
therapy is a cancer treatment that uses high-energy x-rays
or other types of radiation
to kill cancer cells.
There are two types of radiation therapy. External
radiation therapy uses a machine outside the body to send radiation toward
the cancer. Internal
radiation therapy uses a radioactive
substance sealed in needles, seeds, wires, or catheters
that are placed directly into or near the cancer. The way the radiation therapy
is given depends on the type and stage
of the cancer being treated.
Chemotherapy
Chemotherapy
is a cancer treatment that uses drugs to stop the growth of cancer cells, either
by killing the cells or by stopping the cells from dividing. When chemotherapy
is taken by mouth or injected into a vein or muscle, the drugs enter the
bloodstream and can reach cancer cells throughout the body (systemic
chemotherapy). When chemotherapy is placed directly in the spinal column, a
body cavity such as the abdomen,
or an organ,
the drugs mainly affect cancer cells in those areas. The way the chemotherapy is
given depends on the type and stage of the cancer being treated.
Because radiation therapy can affect growth and brain development in young
children, clinical trials are studying ways of using chemotherapy to delay or
reduce the need for radiation therapy.
Cerebrospinal fluid diversion
Cerebrospinal
fluid diversion is a method used to drain fluid that has built up around the
brain and spinal cord. A shunt
(a long, thin tube) is placed in a ventricle (fluid-filled cavity) of the brain
and threaded under the skin to another part of the body, usually the abdomen.
The shunt acts as a drainpipe to carry excess fluid away from the brain so it
may be absorbed elsewhere in the body.
Other types of treatment are being tested in clinical trials.
High-dose chemotherapy with bone marrow transplantation or stem cell
transplantation and radiation therapy
High-dose chemotherapy with bone
marrow or stem
cell transplantation is a method of giving very high doses of chemotherapy
and then replacing blood-forming cells destroyed by the cancer treatment. Stem
cells (immature blood cells) are removed from the bone
marrow or blood of the patient or a donor and are frozen for storage. After
the chemotherapy is completed, the stored stem cells are thawed and given back
to the patient through an infusion.
Over a short time, these reinfused stem cells grow into (and restore) the body's
blood cells. Clinical trials are studying the use of this treatment followed by
radiation therapy directed at the tumor only for childhood medulloblastoma.
Untreated Childhood Medulloblastoma
Untreated childhood medulloblastoma
is a tumor
for which no treatment has been given. The child may have received drugs or
treatment to relieve symptoms
caused by the tumor.
Treatment of average risk childhood medulloblastoma may include the
following:
- Surgery.
- Radiation
therapy to the brain and spinal cord with or without chemotherapy.
Treatment of poor risk childhood medulloblastoma may include the following:
- Surgery.
- Radiation therapy to the brain and spinal cord.
- Chemotherapy.
Treatment of childhood medulloblastoma in children younger than 3 years of
age may include the following:
- Surgery.
- Chemotherapy.
- Radiation therapy with or without chemotherapy.
- A clinical
trial of chemotherapy to delay or reduce the need for radiation therapy.
Recurrent Childhood Medulloblastoma
Treatment of recurrent childhood medulloblastoma may include the following:
- Surgery with or without chemotherapy.
- A clinical trial of high-dose chemotherapy and bone
marrow transplantation or peripheral
blood stem cell transplantation with radiation therapy.
- A clinical trial of a new therapy.
Cancer Glossary Terms
abdomen (AB-do-men)
The area of the body that contains the pancreas, stomach, intestine, liver,
gallbladder, and other organs.
biopsy (BY-op-see)
The removal of cells or tissues for examination under a microscope. When only
a sample of tissue is removed, the procedure is called an incisional biopsy or
core biopsy. When an entire lump or suspicious area is removed, the procedure
is called an excisional biopsy. When a sample of tissue or fluid is removed
with a needle, the procedure is called a needle biopsy or fine-needle
aspiration.
bone marrow
The soft, sponge-like tissue in the center of most large bones. It produces
white blood cells, red blood cells, and platelets.
bone marrow biopsy (BY-op-see)
The removal of a sample of tissue from the bone marrow with a needle for
examination under a microscope.
bone marrow transplantation (trans-plan-TAY-shun)
A procedure to replace bone marrow that has been destroyed by treatment with
high doses of anticancer drugs or radiation. Transplantation may be autologous
(an individual's own marrow saved before treatment), allogeneic (marrow
donated by someone else), or syngeneic (marrow donated by an identical twin).
bone scan
A technique to create images of bones on a computer screen or on film. A small
amount of radioactive material is injected into a blood vessel and travels
through the bloodstream; it collects in the bones and is detected by a
scanner.
cancer
A term for diseases in which abnormal cells divide without control. Cancer
cells can invade nearby tissues and can spread through the bloodstream and
lymphatic system to other parts of the body. There are several main types of
cancer. Carcinoma is cancer that begins in the skin or in tissues that line or
cover internal organs. Sarcoma is cancer that begins in bone, cartilage, fat,
muscle, blood vessels, or other connective or supportive tissue. Leukemia is
cancer that starts in blood-forming tissue such as the bone marrow, and causes
large numbers of abnormal blood cells to be produced and enter the
bloodstream. Lymphoma is cancer that begins in the cells of the immune system.
catheter (KATH-i-ter)
A flexible tube used to deliver fluids into or withdraw fluids from the body.
cell
The individual unit that makes up all of the tissues of the body. All living
things are made up of one or more cells.
central nervous system
CNS. The brain and spinal cord.
cerebellum (ser-uh-BEL-um)
The portion of the brain in the back of the head between the cerebrum and the
brain stem. The cerebellum controls balance for walking and standing, and
other complex motor functions.
cerebrospinal fluid (seh-REE-broe-SPY-nal)
CSF. The fluid flowing around the brain and spinal cord. Cerebrospinal fluid
is produced in the ventricles in the brain.
cerebrospinal fluid diversion
A process used to drain fluid that has built up around the brain and spinal
cord. A shunt (a long, thin tube) is placed in a ventricle of the brain and
threaded under the skin to another part of the body, usually the abdomen. The
shunt carries excess fluid away from the brain so it may be absorbed elsewhere
in the body.
chemotherapy (kee-mo-THER-a-pee)
Treatment with anticancer drugs.
clinical trial
A type of research study that tests how well new medical treatments or other
interventions work in people. Such studies test new methods of screening,
prevention, diagnosis, or treatment of a disease. The study may be carried out
in a clinic or other medical facility. Also called a clinical study.
CT scan
Computed tomography scan. A series of detailed pictures of areas inside the
body taken from different angles; the pictures are created by a computer
linked to an x-ray machine. Also called computerized tomography and
computerized axial tomography (CAT) scan.
endocrinologist (en-do-krih-NAH-lo-jist)
A doctor who specializes in diagnosing and treating hormone disorders.
external radiation (ray-dee-AY-shun)
Radiation therapy that uses a machine to aim high-energy rays at the cancer.
Also called external-beam radiation.
infusion
A method of putting fluids, including drugs, into the bloodstream. Also called
intravenous infusion.
internal radiation (ray-dee-AY-shun)
A procedure in which radioactive material sealed in needles, seeds, wires, or
catheters is placed directly into or near a tumor. Also called brachytherapy,
implant radiation, or interstitial radiation therapy.
leukemia (loo-KEE-mee-a)
Cancer that starts in blood-forming tissue such as the bone marrow, and causes
large numbers of blood cells to be produced and enter the blood stream.
lumbar puncture
A procedure in which a needle is put into the lower part of the spinal column
to collect cerebrospinal fluid or to give anticancer drugs intrathecally. Also
called a spinal tap.
lymphoma (lim-FO-ma)
Cancer that begins in cells of the immune system. There are two basic
categories of lymphomas. One kind is Hodgkin's lymphoma, which is marked by
the presence of a type of cell called the Reed-Sternberg cell. The other
category is non-Hodgkin's lymphomas, which includes a large, diverse group of
cancers of immune system cells. Non-Hodgkin's lymphomas can be further divided
into cancers that have an indolent (slowly progressing) course and those that
have an aggressive (rapidly progressing) course. These subtypes behave and
respond to treatment differently. Both Hodgkin's and non-Hodgkin's lymphomas
can occur in children and adults, and prognosis and treatment depend on the
stage and the type of cancer.
medical oncologist (MED-I-kul on-KOL-o-jist)
A doctor who specializes in diagnosing and treating cancer using chemotherapy,
hormonal therapy, and biological therapy. A medical oncologist often is the
main person who provides direct care for someone who has cancer and who
coordinates treatment provided by other specialists.
medulloblastoma (MED-yoo-lo-blas-TOE-ma)
A malignant brain tumor that begins in the lower part of the brain and that
can spread to the spine or to other parts of the body. Medulloblastomas are a
type of primitive neuroectodermal tumor (PNET).
metastatic cancer
Cancer that has spread from the place in which it started to other parts of
the body.
MRI
Magnetic resonance imaging (mag-NET-ik REZ-o-nans IM-a-jing). A procedure in
which radio waves and a powerful magnet linked to a computer are used to
create detailed pictures of areas inside the body. These pictures can show the
difference between normal and diseased tissue. MRI makes better images of
organs and soft tissue than other scanning techniques, such as CT or X-ray.
MRI is especially useful for imaging the brain, spine, the soft tissue of
joints, and the inside of bones. Also called nuclear magnetic resonance
imaging.
neurologist (noo-ROL-o-jist)
A doctor who specializes in the diagnosis and treatment of disorders of the
nervous system.
neurosurgeon (NOO-ro-SER-jun)
A doctor who specializes in surgery on the brain, spine, and other parts of
the nervous system.
oncologist (on-KOL-o-jist)
A doctor who specializes in treating cancer. Some oncologists specialize in a
particular type of cancer treatment. For example, a radiation oncologist
specializes in treating cancer with radiation.
organ
A part of the body that performs a specific function. For example, the heart
is an organ.
pathologist (pa-THOL-o-jist)
A doctor who identifies diseases by studying cells and tissues under a
microscope.
pediatric (pee-dee-AT-rik)
Having to do with children.
peripheral stem cell transplantation (per-IF-er-al)
A method of replacing blood-forming cells destroyed by cancer treatment.
Immature blood cells (stem cells) in the circulating blood that are similar to
those in the bone marrow are given to the patient after treatment. This helps
the bone marrow recover and continue producing healthy blood cells.
Transplantation may be autologous (an individual's own blood cells saved
earlier), allogeneic (blood cells donated by someone else), or syngeneic
(blood cells donated by an identical twin). Also called peripheral stem cell
support.
primary tumor
The original tumor.
prognosis (prog-NO-sis)
The likely outcome or course of a disease; the chance of recovery or
recurrence.
psychologist
A specialist who can talk with patients and their families about emotional and
personal matters, and can help them make decisions.
radiation (ray-dee-AY-shun)
Energy released in the form of particles or electromagnetic waves. Common
sources of radiation include radon gas, cosmic rays from outer space, and
medical x-rays.
radiation oncologist (ray-dee-AY-shun on-KOL-o-jist)
A doctor who specializes in using radiation to treat cancer.
radiation therapy (ray-dee-AY-shun)
The use of high-energy radiation from x-rays, gamma rays, neutrons, and other
sources to kill cancer cells and shrink tumors. Radiation may come from a
machine outside the body (external-beam radiation therapy), or from materials
called radioisotopes. Radioisotopes produce radiation and can be placed in or
near the tumor or in the area near cancer cells. This type of radiation
treatment is called internal radiation therapy, implant radiation,
interstitial radiation, or brachytherapy. Systemic radiation therapy uses a
radioactive substance, such as a radiolabeled monoclonal antibody, that
circulates throughout the body. Also called radiotherapy, irradiation, and
x-ray therapy.
radioactive (RAY-dee-o-AK-tiv)
Giving off radiation.
radioactive seed
A small, radioactive pellet that is placed in or near a tumor. Cancer cells
are killed by the energy given off as the radioactive material decays (breaks
down).
recur
To occur again.
recurrent cancer
Cancer that has returned after a period of time during which the cancer could
not be detected. The cancer may come back to the same site as the original
(primary) tumor or to another place in the body.
rehabilitation specialist
A health care professional who helps people recover from an illness or injury
and return to daily life. Examples of rehabilitation specialists are physical
therapists and occupational therapists.
secondary tumor
Cancer that has spread from the organ in which it first appeared to another
organ. For example, breast cancer cells may spread (metastasize) to the lungs
and cause the growth of a new tumor. When this happens, the disease is called
metastatic breast cancer and the tumor in the lungs is called a secondary
tumor. Also called secondary cancer.
shunt
A surgeon implants or creates a shunt to move blood or other fluid from one
part of the body to another part. For example, a surgeon may implant a tube to
drain cerebrospinal fluid from the brain to the abdomen. A surgeon may also
change normal blood flow by joining two blood vessels together.
stage
The extent of a cancer within the body. If the cancer has spread, the stage
describes how far it has spread from the original site to other parts of the
body.
standard therapy
A currently accepted and widely used treatment for a certain type of cancer,
based on the results of past research.
stem cell
A cell from which other types of cells can develop.
surgery (SER-juh-ree)
A procedure to remove or repair a part of the body or to find out whether
disease is present. An operation.
symptom
An indication that a person has a condition or disease. Some examples of
symptoms are headache, fever, fatigue, nausea, vomiting, and pain.
systemic chemotherapy
Treatment with anticancer drugs that travel through the bloodstream, reaching
and affecting cells all over the body.
tissue (TISH-oo)
A group or layer of cells that are alike and that work together to perform a
specific function.
tumor (TOO-mer)
An abnormal mass of tissue that results from excessive cell division. Tumors
perform no useful body function. They may be benign (not cancerous) or
malignant (cancerous).
x-ray
A type of high-energy radiation. In low doses, x-rays are used to diagnose
diseases by making pictures of the inside of the body. In high doses, x-rays
are used to treat cancer.
Source: National Institutes of Health; National Cancer Institute
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