Channels — called lymphatics or lymph vessels— connect
the parts of the lymphatic system.
Lymphoma is a type of cancer
that begins in lymphatic tissue. There are several different types of lymphomas.
Some involve lymphoid cells and are grouped under the heading of Hodgkin lymphoma. All other forms of lymphoma fall into the non-Hodgkin
Lymphomas that involve a type of cell called a Reed-Sternberg cell are classified
as Hodgkin lymphoma. Different
types of Hodgkin lymphoma are classified based on how the cancerous tissue looks under
a microscope. Hodgkin lymphoma affects about 3
out of every 100,000 Americans, most commonly during early and late adulthood (between
ages 15 and 40 and after age 55).
The most common first symptom of Hodgkin lymphoma is a painless enlargement of
the lymph nodes (a condition known as swollen glands) in the neck,
above the collarbone, in the underarm area, or in the groin.
If Hodgkin lymphoma involves the lymph nodes in the center of the chest, pressure
from this swelling may cause an unexplained cough, shortness of breath, or problems
in blood flow to and from the heart.
Some people have other symptoms including fatigue (tiredness), poor appetite, itching,
or hives. Unexplained fever, night sweats, and weight loss are also common.
Non-Hodgkin Lymphoma (NHL)
Non-Hodgkin lymphoma (NHL)
can happen at any age during childhood, but is rare before age 3. NHL is slightly
more common than Hodgkin disease in kids younger than 15 years old.
In non-Hodgkin lymphoma, there is malignant (cancerous)
growth of specific types of lymphocytes (a kind of white blood cell that collects in the lymph nodes).
Risk for Childhood Lymphoma
Both Hodgkin lymphoma and non-Hodgkin lymphoma tend to happen more often in people
with certain severe immune deficiencies, including:
those with inherited immune defects (defects passed down by parents)
those treated with immunosuppressive drugs after
organ transplants (these strong drugs help hold back the activity of the immune system)
Kids who have had either radiation therapy or
chemotherapy for other types of cancer seem to have a higher risk of developing
lymphoma later in life.
Regular pediatric checkups can sometimes spot early symptoms when lymphoma is linked
to an inherited immune problem, HIV infection, treatment with immunosuppressive drugs,
or prior cancer treatment.
No lifestyle factors have been definitely linked
to childhood lymphomas. Usually, neither parents nor kids have control
over what causes lymphomas. Most cases are due to noninherited mutations (errors)
in the genes of growing blood cells.
Doctors will check a child's weight and do a physical examination to look for enlarged
lymph nodes and signs of infection. Using a stethoscope, they'll examine the chest and feel the abdomen to check for pain, organ enlargement,
or fluid build-up.
In addition to the physical exam, doctors take a medical history
by asking about the child's past health, his or her family's health, and other issues.
Sometimes, when a child has an enlarged lymph node for no apparent reason, the
doctor will watch the node closely to see if it continues to grow. The doctor may
prescribe antibiotics if the gland is thought to be infected by bacteria, or do blood
tests for certain types of infection.
If the lymph node stays enlarged, the next step is a biopsy (removing
and examining tissue, cells, or fluids from the body). Biopsies are also necessary
for lymphomas that involve the bone marrow or structures in the chest or abdomen.
The biopsy may be done using a thin hollow needle (this is known as needle aspiration).
Or, a small surgical incision might be made while the patient is under general anesthesia. Sometimes,
a biopsy may require a surgical excision under anesthesia. This means
a piece of the lymph node or the entire lymph node is removed.
In the laboratory, tissue samples from the biopsy are examined to determine the
specific type of lymphoma. Besides these basic lab tests, more sophisticated tests
are usually done, including genetic
studies, to distinguish between specific types of lymphoma.
To identify which areas of the body are affected by lymphoma, these tests are also
computed tomography (CT) of the chest and abdomen, and sometimes X-rays
magnetic resonance imaging (MRI)
bone scan, gallium scan, and/or positron emisson tomography (PET) scan (when a
radioactive material is injected into the bloodstream to look for evidence of tumors
throughout the body)
These tests help doctors decide which type of treatment to use.
Treatment of childhood lymphoma is largely determined by staging.
Staging is a way to categorize or classify patients according to how extensive the
disease is at the time of diagnosis.
Chemotherapy (the use of highly potent medical drugs to kill cancer cells) is the
main form of treatment for all types of lymphoma. In certain cases, radiation (using high-energy rays to kill cancer cells and keep them
from growing and multiplying) may also be used.
Short-Term and Long-Term Side Effects
Chemotherapy for lymphoma affects the bone marrow, causing anemia
and bleeding problems, and increases a person's risk for serious infections.
Chemotherapy and radiation treatments have many other side
effects — some short-term
(such as hair loss, changes in skin color, increased infection risk, and nausea and
vomiting) and some long-term
(such heart and kidney damage, reproductive problems, thyroid problems, or the development
of another cancer later in life).
Parents should discuss all potential side effects with their child's care team.
Although most kids recover from lymphoma, some with severe lymphoma will have a
relapse (reappearance of the cancer). For these children, bone marrow transplants
and stem cell transplants
are often among the treatment options.
During a bone marrow/stem cell transplant, chemotherapy with or without radiation
therapy is given to kill cancerous cells. Then, healthy bone marrow/stem cells are
introduced into the body. These healthy cells can produce white blood cells that will
help the child fight infections.
New treatments for childhood lymphomas include several different types of immune
therapy, specifically using antibodies to deliver chemotherapy medicines or radioactive
chemicals directly to lymphoma cells. (Antibodies are proteins made by the immune
system to fight bacteria, viruses,
and toxins.) This direct targeting of lymphoma cells can help a person avoid the side
effects that happen when chemotherapy and radiation treatments damage normal, noncancerous