Hodgkin lymphoma is caused by malfunctioning lymphocytes, white blood cells that usually help our bodies fight infection.
What is Hodgkin lymphoma?
In people with lymphoma, something goes wrong inside the lymphocytes.
- Lymphocytes are a type of white blood cell made in the bone marrow and found in the blood and lymph tissue.
- In lymphoma, the lymphocytes don’t mature and can’t carry out their normal immune functions defending against infection.
- The lymphoma cells don’t die off like should but instead collect in the lymph nodes.
- Most often Hodgkin lymphoma starts in the lymph nodes in the upper part of the body — in the neck or chest or under the arms.
- It can spread through the lymph system to nearby lymph nodes and outside the lymph nodes to the bone marrow, lungs or liver.
- Hodgkin lymphoma can be cured or controlled for many years in most people who have the disease.
Understanding your lymph system
To understand lymphoma, it helps to know the basics about your lymph system.
What is the lymph system?
The lymph system is a network of tubes (lymphatic vessels) that slowly carry fluid from your tissues into your bloodstream to be recycled. The fluid (lymph) contains waste products from body tissues as well as immune system cells.
What are lymph nodes?
Lymph nodes are small bean-shaped organs linked by your lymphatic vessels. They are part of your immune system. They store lymphocytes and act as filters to trap foreign particles.
Where are these nodes?
Lymph nodes are located throughout your body in your neck, underarms and groin and behind your knees. They are also deeper inside your body in your chest, abdomen and pelvic area.
What else makes up the lymph system?
Along with lymph nodes, you have other lymph tissue, including organs related to your immune and blood-forming systems, such as your spleen, thymus and bone marrow.
How do lymphocytes protect the body?
There are several kinds of lymphocytes.
- B lymphocytes, or B cells. These make antibodies. Antibodies attach to bacteria and to cells infected with a virus or bacteria so that other immune cells recognize them and know to destroy them.
- T lymphocytes, or T cells. These are involved in destroying invaders or tumor cells or in attracting or stimulating other immune cells to do this.
- Natural killer cells. These scout for abnormal cells and destroy them.
Types of Hodgkin lymphoma
It’s important to correctly identify the type and subtype of your lymphoma to determine which treatments are most likely to be effective.
There are two main types of lymphoma:
- Hodgkin lymphoma, which involves Reed-Sternberg cells, abnormal B cells
- Non-Hodgkin lymphoma, in which there are no Reed-Sternberg cells
Within Hodgkin lymphoma, there are two types.
- Classic Hodgkin lymphoma, about 95 percent of cases
- Nodular lymphocyte predominant, about 5 percent of cases
Classic Hodgkin lymphoma
There are four subtypes of classic Hodgkin lymphoma, named for:
- What’s happening to the lymph nodes
- Which kinds of immune-system cells are involved along with Reed-Sternberg cells
The subtypes are called:
- Nodular sclerosis
- Mixed cellularity
- Lymphocyte rich
- Lymphocyte depleted
Nodular lymphocyte predominant lymphoma
This type involves nodules made up of lymphocytes and a variation of Reed-Sternberg cells sometimes called popcorn cells because of the way they look. Over time, about 10 percent of these lymphomas transform into aggressive diffuse B-cell lymphoma, a type of non-Hodgkin lymphoma.
Symptoms of Hodgkin lymphoma
The symptoms of Hodgkin lymphoma may be similar to symptoms caused by other conditions that are not related to cancer. Check with your a doctor if you feel concerned about any symptoms you have.
Symptoms of Hodgkin lymphoma include:
- Painless swollen lymph nodes in your neck, underarm, groin, chest or abdomen
- Unexplained fever, weight loss or night sweats — sometimes called “B symptoms”
- Ongoing fatigue
- Itchy skin
- Swelling in your face, neck or upper chest
- Feeling of fullness in your abdomen (from an enlarged liver, spleen, or lymph nodes)
- Abdominal problems, such as nausea, vomiting and indigestion
- Sensitivity to alcohol or pain in your lymph nodes after having alcohol
- Coughing, trouble breathing or chest pain
Usually lymph-node symptoms, like swelling, come on slowly. For instance, a person may have some swelling for as long as a year before diagnosis.
Diagnosing Hodgkin lymphoma
If your doctor suspects you may have lymphoma, they will do a physical exam to look for signs of the disease and ask about your health history.
To confirm the presence of lymphoma, you will need a biopsy. This means removing part or all of a lymph node or a small sample of tissue surgically or with a needle. Experts in identifying blood-related cancers (hematopathologists) look at the cells under a microscope to diagnose the disease and accurately identify the type.
You might also have any or all of these tests:
- Imaging tests — such as a chest X-ray, ultrasound, magnetic resonance imaging (MRI), computed tomography (CT) scan or positron emission tomography (PET) scan to see pictures of the inside of your body and look for enlarged lymph nodes, tumors or other cancer activity
- Blood tests — to check the types and numbers of blood cells (complete blood count) and look for chemicals that signal disease in certain organs or tissues (blood chemistry analysis)
- Bone marrow tests — taking samples of bone marrow and a small piece of bone from your pelvis using a needle (bone marrow aspiration and biopsy) to check for cancer cells
If you have lymphoma, you may need more tests to identify the type. These include an immunohistochemistry study; immunophenotyping, or flow cytometry; and cytogenetic analysis.
Stages of Hodgkin lymphoma
Staging means finding out how far lymphoma has spread in your lymph system or other parts of your body. Accurate staging allows your doctors to choose the most appropriate therapy for you — and help you avoid therapy that is not likely to be effective in your situation.
Hodgkin lymphomas range from stage I to stage IV, with I being the least advanced and IV being the most advanced.
Doctors may add a letter after your stage to describe more about your disease.
- A (such as “stage IA”) means you do not have symptoms.
- B (such as “stage IB”) means you have B symptoms: fever, weight loss or night sweats.
- E (such as “stage IIIE”) means your cancer is outside your lymph system (extranodal).
- S (such as “stage IIIS”) means the cancer is in your spleen.
To further understand your lymphoma and recommend the best treatment for you, your doctor will use many other factors, such as whether you have:
- A tumor in your chest above a certain size
- Cancer in an organ other than your lymph nodes
- Three or more lymph nodes with cancer
- A high sedimentation rate (your red blood cells settle quickly to the bottom of a test tube in a sample of your blood)
- Certain levels of blood albumin, hemoglobin, white blood cells and lymphocytes
If your lymphoma comes back after treatment, it is called recurrent or relapsed. Your doctor will order imaging tests or other tests to restage it.
How common is Hodgkin lymphoma?
About 8,300 people are newly diagnosed with Hodgkin lymphoma in the United States each year.
What causes Hodgkin lymphoma?
Doctors do not know what causes Hodgkin lymphoma. It is more common in men than in women and more common in people age 15 to 35 or over 50.
You may be at higher risk if any of these is true:
- Your immune system is weakened by an inherited disease, autoimmune disease, human immunodeficiency virus (HIV) or drugs given because you had an organ transplant.
- You have been infected with Epstein-Barr virus (which causes mononucleosis).
- Your brother or sister had Hodgkin lymphoma.
Keep in mind that most people who get the disease have none of these risk factors, and most people with these risk factors do not develop the disease.