Hodgkin lymphoma is a cancer of the immune system. It is also called Hodgkin disease. Hodgkin lymphoma is one of the most curable forms of cancer. It begins in the part of the immune system called the lymph system. The lymph system is made up of an intricate network of immune cells, small blood-vessel-like structures called lymphatics, and lymph nodes. It also includes organs made primarily of immune cells such as the spleen and thymus gland. The lymph (or lymphatic) system helps fights infections and other diseases.
The lymph system includes:
Lymph: A clear fluid that carries white blood cells (especially lymphocytes) through the lymph system. White blood cells help fight infection.
Lymph vessels: A network of thin tubes. They carry lymph from different parts of the body to the bloodstream.
Lymph nodes: Small masses of tissue that store white blood cells. They also remove bacteria and other substances from the lymph. Lymph nodes reside in the neck, underarms, chest, abdomen, pelvis, and groin.
Spleen: An organ near the stomach that:
Filters the blood
Stores blood cells
Destroys old blood cells
Thymus gland: a gland of lymphocytes that are important in immune function especially in children and young adults
The lymph system also consists of the thymus, tonsils, and bone marrow and gastrointestinal tract.
Hodgkin lymphoma can begin almost anywhere. It can spread to almost any tissue or organ. The disease starts when a change occurs to the genetic material of a lymphocyte. This turns the lymphocyte into a large, abnormal cell. Hodgkin lymphoma is distinguished by these unique cancer cells, called Reed-Sternberg cells. The abnormal cells begin dividing out of control. They often go on to form tumor masses in lymph nodes and elsewhere.
Most patients with Hodgkin lymphoma can be cured or have their disease controlled for many years.