Hodgkin disease (Hodgkin lymphoma) is a type of lymphoma, a cancer that starts in white blood cells called lymphocytes. Lymphocytes are part of the immune system.
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 spread to other areas of the body. To learn more about how cancers start and spread, see What Is Cancer?
Types of lymphoma
There are 2 kinds of lymphoma:
- Hodgkin disease (named after Dr. Thomas Hodgkin, who first described it)
- Non-Hodgkin lymphoma
These types of lymphomas differ in how they behave, spread, and respond to treatment, so it’s important to tell them apart. Doctors can most often tell the difference between them by looking at the cancer cells under a microscope. Sometimes, lab tests might be needed to do this.
Both children and adults can get Hodgkin disease. This document covers treatment in both groups.
To learn about non-Hodgkin lymphoma, see Non-Hodgkin Lymphoma.
The lymph system and lymphoid tissue
To understand Hodgkin disease, it helps to know about the body’s lymph system. The lymph system is part of the immune system, which helps fight infections. The lymph system is made up of lymphoid tissue, lymph vessels, and a clear fluid called lymph.
Lymphoid tissue includes the lymph nodes and other organs that are part of the body’s immune and blood-forming systems. Lymph nodes are bean-size collections of lymphoid tissue in many places throughout the body. Other parts of the lymph system include the spleen, the bone marrow (soft inner part of some bones), the tonsils, and the thymus. Lymphoid tissue can also be found in other organs, such as the stomach and intestines.
Lymphoid tissue is made up mainly of lymphocytes, which are special white blood cells that fight infection. There are 2 types of lymphocytes:
- B lymphocytes (or B cells)
- T lymphocytes (or T cells)
Almost all cases of Hodgkin disease start in B lymphocytes.
Start and spread of Hodgkin disease
Lymphoid tissue is found in many parts of the body, so Hodgkin disease can start almost anywhere. Most often it starts in lymph nodes in the upper part of the body (in the chest, neck, or under the arms).
Hodgkin disease can spread through the lymph vessels in a stepwise fashion from lymph node to lymph node. Rarely, and late in the disease, the cancer can get into the blood vessels and then spread to almost any other place in the body.
Types of Hodgkin disease
The main types of Hodgkin disease are:
- Classic Hodgkin disease (which has 4 subtypes), which accounts for about 95% of cases
- Nodular lymphocyte predominant Hodgkin disease (NLPHD), which makes up about 5% of cases
These types differ in the way the cancer cells look under a microscope. The types are important because they grow and spread in different ways. Often they are treated in different ways. You can ask your doctor about the exact type of Hodgkin disease you (or your loved one) has.
All types of Hodgkin disease are cancer because as they grow they can invade (grow into) nearby normal tissues and spread to other parts of the body.
Last Revised: 02/09/2016