What Is Lymphoma?
The lymph system is a series of lymph nodes and
vessels that move lymph fluid through the body. Lymph fluids contain
infection-fighting white blood cells. Lymph nodes act as filters, capturing and
destroying bacteria and viruses to prevent infection from spreading.
While the lymph system typically protects your
body, lymph cells called lymphocytes can become cancerous. The names for
cancers that occur in the lymph system are lymphomas. According to the Memorial Sloan Kettering Cancer Center
(MSKCC), an estimated 75,000 Americans are
diagnosed with lymphoma each year.
Doctors classify more than 60 cancer types as
lymphomas. Lymphomas can affect any portion of the lymphatic system, including:
- bone marrow
- lymph nodes
Doctors typically divide lymphomas into two
categories, Hodgkin lymphoma and non-Hodgkin lymphoma.
What Are the Types of Lymphoma?
The two major lymphoma types are
Hodgkin lymphoma and non-Hodgkin lymphoma (NHL). A pathologist in the 1800s
named Dr. Thomas Hodgkin identified the cells in what is now called Hodgkin
lymphoma. Those with Hodgkin lymphoma have large cancerous cells called
Reed-Sternberg cells. People with NHL don’t have these cells.
According to the Leukemia &
Lymphoma Society (LLS), NHL is three times more common than Hodgkin
Many lymphoma types fall under each category. Doctors call NHL types by
the cells they affect, and if the cells are fast- or slow-growing. NHL forms in
either the B-cells or T-cells of the immune system. According to LLS, most NHL
types affect B-cells. Types include:
- B-cell lymphoma
- Burkitt lymphoma
- follicular lymphoma
- mantle cell lymphoma
- primary mediastinal B cell lymphoma
- small lymphocytic lymphoma
- Waldenstrom macroglobulinemia (also known as
Hodgkin lymphomas typically start in B-cells or immune system cells
known as Reed-Sternberg cells. Hodgkin lymphoma types include:
- lymphocyte-depleted Hodgkin disease
- lymphocyte-rich Hodgkin disease
- mixed cellularity Hodgkin lymphoma
- nodular lymphocyte-predominant Hodgkin disease
(a rare form)
- nodular sclerosis Hodgkin lymphoma
What Are Risk Factors for Lymphoma?
Most diagnosed lymphoma cases have no known cause. However, some people
are considered higher risk. This includes people with immune system disorders,
- human immunodeficiency virus (HIV)
- those who take anti-rejection medications after
- those with a genetic immune system disorder
People who have had infections
such as the human T-cell leukemia/lymphotropic virus (HTLV-1), Heliobacter pylori, hepatitis C, or the
Epstein-Barr virus are associated with an increased risk. Those exposed to
chemicals in pesticides, fertilizers, and herbicides are also at increased
risk. Exposure to these infections or chemicals doesn’t mean a person will get
People who have undergone
radiation treatments in the past also have a greater chance of having lymphoma.
What Are the Symptoms of Lymphoma?
According to LLS,
most patients with lymphoma first notice swollen lymph nodes. These may feel
like small, soft nodules under the skin. A person may feel the lymph nodes in
- upper chest
Other lymphoma symptoms include:
- bone pain
- enlarged spleen
- night sweats
- pain when drinking alcohol
- shortness of breath
- skin itching
- stomach pain
- unexplained weight loss
Lymphoma may not always cause
symptoms in its early stages. A doctor may discover enlarged lymph nodes during
a physical examination.
How Is Lymphoma Diagnosed?
A biopsy typically is taken if a doctor suspects lymphoma. This
involves removing cells from an enlarged lymph node. A doctor known as a
hematopathologist will examine the cells to determine if lymphoma cells are
present and what cell type they are.
If the hematopathologist detects lymphoma cells, further
testing can identify how far the cancer has spread. These tests can include a
chest X-ray, blood testing, or testing nearby lymph nodes or tissues. Imaging
scans, such as a computed tomography (CT) or magnetic resonance imaging (MRI)
scans may also identify additional tumors or enlarged lymph nodes.
How Is Lymphoma Treated?
A number of medical specialists
collaborate to treat lymphoma. These include hematologists, doctors who specialize
in blood, bone marrow, and immune cell disorders. Oncologists treat cancerous
tumors. Pathologists may work with these doctors to assist in treatment
planning and identify if a particular treatment is working.
Lymphoma treatments depend upon
the cancer’s stage. Doctors will “stage” a tumor to signify how far the
cancerous cells may have spread. A stage 1 tumor is limited to a few lymph
nodes, while a stage 4 tumor has spread to other organs, such as the lungs or
Doctors also “grade” NHL tumors by how fast they’re growing. These
- low-grade or indolent
- intermediate-grade or aggressive
- high-grade or highly aggressive
Treatment for Hodgkin’s lymphoma
includes radiation therapy to shrink and kill cancerous cells. Doctors also
prescribe chemotherapy medications to destroy cancerous cells.
Chemotherapy and radiation are
also used to treat NHL. Biological therapies that target cancerous B-cells also
can be effective. An example of this drug type includes rituximab.
In some instances, a bone marrow
or stem cell transplant is used to build up healthy immune system cells. Doctors
may harvest these cells or tissues before beginning chemotherapy and radiation
treatments. Relatives may be able to donate bone marrow too.
What Is the Survival Outlook for Lymphoma?
According to the Leukemia &
Lymphoma Society, Hodgkin lymphoma is a highly curable cancer. Survival
rates for both NHL and Hodgkin lymphoma depend upon how far the cancerous cells
have spread and the cancer type. According to the
American Cancer Society (ACS), the overall five-year survival rate for NHL
patients is 69 percent and the 10-year survival rate is 58 percent. The
survival rate for Hodgkin lymphoma depends upon its stage. The 5-year survival
rate for stage 1 is 90 percent, while the 5-year survival rate for stage 4 is