Adult Hodgkin lymphoma is a disease in which malignant (cancer) cells form in the lymph system.

Adult Hodgkin lymphoma is a type of cancer that develops in the lymph system, part of the body's immune system.

The lymph system is made up of the following:

• Lymph: Colorless, watery fluid that travels through the lymph system and carries white blood cells called lymphocytes. Lymphocytes protect the body against infections and the growth of tumors.
• Lymph vessels: A network of thin tubes that collect lymph from different parts of the body and return it to the bloodstream.
• Lymph nodes: Small, bean-shaped structures that filter lymph and store white blood cells that help fight infection and disease. Lymph nodes are located along the network of lymph vessels found throughout the body. Clusters of lymph nodes are found in the underarm, pelvis, neck, abdomen, and groin.
• Spleen: An organ that makes lymphocytes, filters the blood, stores blood cells, and destroys old blood cells. It is located on the left side of the abdomen near the stomach.
• Thymus: An organ in which lymphocytes grow and multiply. The thymus is in the chest behind the breastbone.
• Tonsils: Two small masses of lymph tissue at the back of the throat. The tonsils produce lymphocytes.
• Bone marrow: The soft, spongy tissue in the center of large bones. Bone marrow produces white blood cells, red blood cells, and platelets.

Anatomy of the lymph system, showing the lymph vessels and lymph organs including lymph nodes, tonsils, thymus, spleen, and bone marrow. Lymph (clear fluid) and lymphocytes travel through the lymph vessels and into the lymph nodes where the lymphocytes destroy harmful substances. The lymph enters the blood through a large vein near the heart.

Because lymph tissue is found throughout the body, Hodgkin lymphoma can begin in almost any part of the body and spread to almost any tissue or organ in the body.

Lymphomas are divided into two general types: Hodgkin lymphoma and non-Hodgkin lymphoma. This summary is about the treatment of adult Hodgkin lymphoma. (See the PDQ summary on Adult Non-Hodgkin Lymphoma Treatment for more information.)

Hodgkin lymphoma can occur in both adults and children; however, treatment for adults may be different than treatment for children. Hodgkin lymphoma may also occur in patients who have acquired immunodeficiency syndrome (AIDS); these patients require special treatment.

See the following PDQ summaries for more information:

• Childhood Hodgkin Lymphoma Treatment
• AIDS-Related Lymphoma Treatment

Hodgkin lymphoma in pregnant women is the same as the disease in nonpregnant women of childbearing age. However, treatment is different for pregnant women. This summary includes information about treating Hodgkin lymphoma during pregnancy.

There are two main types of Hodgkin lymphoma: classical and nodular lymphocyte-predominant.

Most Hodgkin lymphomas are the classical type. The classical type is broken down into the following four subtypes:

• Nodular sclerosing Hodgkin lymphoma.
• Mixed cellularity Hodgkin lymphoma.
• Lymphocyte depletion Hodgkin lymphoma.
• Lymphocyte-rich classical Hodgkin lymphoma.