What Is Hodgkin Lymphoma?
Cancer starts when cells in the body begin to grow out of control. Cells in nearly any part of the body can become cancer, and can then spread to other areas of the body. To learn more about how cancers start and spread, see What Is Cancer?
Lymphomas are cancers that start in white blood cells called lymphocytes. There are 2 main types of lymphoma. Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL). They behave, spread, and respond to treatment differently, so it's important for you to know which one you have.
This information focuses on Hodgkin Lymphoma. For information on the other type, see Non-Hodgkin Lymphoma.
The lymph system
To understand what Hodgkin lymphoma is, it helps to know about the lymph system (also known as the lymphatic system). The lymph system is part of the immune system, which helps fight infections and some other diseases. It also helps the flow of fluids in the body.
The lymph system is made up mainly of cells called lymphocytes, a type of white blood cell. There are 2 main types of lymphocytes:
- B lymphocytes (B cells): B cells make proteins called antibodies to help protect the body from germs (bacteria and viruses).
- T lymphocytes (T cells): There are several types of T cells. Some T cells destroy germs or abnormal cells in the body. Other T cells help boost or slow the activity of other immune system cells.
Hodgkin lymphoma usually starts in B lymphocytes.
Start and spread of Hodgkin lymphoma
Lymph tissue is in many parts of your body, so Hodgkin lymphoma can start almost anywhere.
The major sites of lymphoid tissue are:
Lymph nodes: Lymph nodes are bean-sized collections of lymphocytes and other immune system cells throughout the body, including inside the chest, abdomen, and pelvis. They are connected to each other by a system of lymphatic vessels.
Spleen: The spleen is an organ under the lower ribs on your left side. The spleen makes lymphocytes and other immune system cells. It also stores healthy blood cells and filters out damaged blood cells, bacteria, and cell waste.
Bone marrow: The bone marrow is the spongy tissue inside certain bones. New blood cells (including some lymphocytes) are made there.
Thymus: The thymus is a small organ behind the upper part of the breastbone and in front of the heart. It is important for T lymphocyte development..
Adenoids and tonsils: These are collections of lymphoid tissue in the back of your throat. They help make antibodies against germs that are breathed in or swallowed.
Digestive tract: The stomach, intestines, and many other organs also have lymph tissue.
Although Hodgkin lymphoma can start almost anywhere, most often it starts in lymph nodes in the upper part of the body. The most common sites are in the chest, neck, or under the arms.
Hodgkin lymphoma most often spreads through the lymph vessels from lymph node to lymph node. Rarely, late in the disease, it can invade the bloodstream and spread to other parts of the body, such as the liver, lungs, and/or bone marrow.
Types of Hodgkin lymphoma
Different types of Hodgkin lymphoma can grow and spread differently and may be treated differently.
Classic Hodgkin lymphoma
Classic Hodgkin lymphoma (cHL) accounts for about 95% of all cases of Hodgkin lymphomas in developed countries.
The cancer cells in cHL are called Reed-Sternberg cells. These cells are usually an abnormal type of B lymphocyte. Enlarged lymph nodes in people with cHL usually have a small number of Reed-Sternberg cells and a large number of surrounding normal immune cells. These other immune cells make up most of the enlarged lymph nodes.
Classic HL has 4 subtypes:
Nodular sclerosis Hodgkin lymphoma: This is the most common type of Hodgkin disease in developed countries. It is most common in teens and young adults, but it can occur in people of any age. It tends to start in lymph nodes in the neck or chest.
Mixed cellularity Hodgkin lymphoma: This is the second most common type and is seen mostly in older adults (although it can occur at any age). It can start in any lymph node but most often occurs in the upper half of the body.
Lymphocyte-rich Hodgkin lymphoma: This subtype usually occurs in the upper half of the body and is rarely found in more than a few lymph nodes.
Lymphocyte-depleted Hodgkin lymphoma: This is the least common form of Hodgkin disease. It is seen mainly in older people. It is more likely to be advanced when first found, in lymph nodes in the abdomen as well as in the spleen, liver, and bone marrow.
Nodular lymphocyte predominant Hodgkin lymphoma
Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) accounts for about 5% of cases. The cancer cells in NLPHL are large cells called popcorn cells (because they look like popcorn), which are variants of Reed-Sternberg cells.
NLPHL usually starts in lymph nodes in the neck and under the arm. It can occur in people of any age, and is more common in men than in women. This type of HL is treated differently from the classic types.
Bartlett NL, Foyil KV. Chapter 105: Hodgkin lymphoma. In: Niederhuber JE, Armitage JO, Dorshow JH, Kastan MB, Tepper JE, eds. Abeloff’s Clinical Oncology. 5th ed. Philadelphia, Pa. Elsevier: 2014.
Younes A, Carbone A, Johnson P, Dabaja B, Ansell S, Kuruvilla J. Chapter 102: Hodgkin’s lymphoma. In: DeVita VT, Lawrence TS, Rosenberg SA, eds. DeVita, Hellman, and Rosenberg’s Cancer: Principles and Practice of Oncology. 10th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2015.
Last Medical Review: February 10, 2017 Last Revised: March 28, 2017