The Basic Facts on Hodgkin’s disease
Learn more about the disease known as Hodgkin’s lymphoma

Hodgkin's disease, sometimes called Hodgkin's lymphoma, is a cancer of lymphatic tissue. Lymphatic tissue comprises lymph nodes and related organs that are part of the body's immune and blood-forming systems. Lymph nodes are small, bean-shaped organs that make and store infection-fighting white blood cells, called lymphocytes. Lymph nodes are found underneath the skin in the neck, underarm, and groin that are also found in many other places in the body such as inside the chest, abdomen, and pelvis.
Lymph nodes are connected throughout the body by lymph vessels (narrow tubes similar to blood vessels), which carry a colorless, watery fluid (lymphatic fluid) that contains lymphocytes.
The lymphatic system also includes the spleen, the bone marrow, and the thymus. The bone marrow is the spongy tissue inside the bones that creates new red and white blood cells including lymphocytes. The spleen is an organ that removes old blood and debris from the cells. It is located on the left side of the upper abdomen that is composed primarily of mature and immature lymphocytes. The thymus is a small organ in the chest that is important in developing a special lymphocyte called a T cell.
Hodgkin's disease can start almost anywhere, since lymphatic tissue is present in many parts of the body, but most often starts in lymph nodes in the upper part of the body. The chest, neck, or under the arms are the most common sites. Hodgkin's disease enlarges the lymphatic tissue, and causes pressure on important structures. It spreads through the lymphatic vessels to other lymph nodes. Most Hodgkin's disease spreads to nearby lymph node sites in the body and rarely gets into the blood vessels. It can spread to almost any other site in the body, including the liver and lungs.
Lymph nodes may enlarge for several reasons. In fact, although Hodgkin’s disease can be one cause for lymph node enlargement, enlarged lymph nodes are more commonly a result of the body fighting an infection.
Hodgkin's disease is a cancer of lymphatic tissue, which is called a lymphoma. There are two major types of lymphomas: Hodgkin's disease, and non-Hodgkin's lymphomas. 
The cancer cells in Hodgkin's disease are called Reed-Sternberg cells, named for the scientists who first described them, and they are different in appearance from non-Hodgkin’s lymphomas when examined under a microscope. Most scientists now believe that Reed-Sternberg cells are a type of malignant B lymphocyte. Normal B lymphocytes are the cells that make antibodies that help fight infections.
Hodgkin's disease is divided into further types and subtypes which doctors have identified. The two main types are classical Hodgkin's disease (which has several subtypes) and nodular predominant Hodgkin's disease.