What is Castleman disease?
Castleman disease (CD) is a rare disease of lymph nodes and related tissues. It is also known as Castleman’s disease, giant lymph node hyperplasia, and angiofollicular lymph node hyperplasia (AFH). It was first described by Dr. Benjamin Castleman in the 1950s.
CD is not cancer. Instead, it is called a lymphoproliferative disorder. This means there is an abnormal overgrowth of cells of the lymph system that is similar in many ways to lymphomas (cancers of lymph nodes).
Even though CD is not officially a cancer, one form of this disease (known as multicentric Castleman disease) acts very much like lymphoma. In fact, many people with this disease eventually develop lymphomas. And like lymphoma, CD is often treated with chemotherapy or radiation therapy. This is why it is included in the American Cancer Society’s cancer information. (For information about lymphoma, see our documents Hodgkin Disease and Non-Hodgkin Lymphoma.)
About lymph nodes and lymphoid tissue
To understand Castleman disease, it helps to know about the body’s lymph system.
Lymphoid tissue, also known as lymphatic tissue, is the main part of the immune system. It is formed by different types of cells that work together to help the body fight infections. The main cells in lymphoid tissue are lymphocytes, a type of white blood cell. There are 2 main types of lymphocytes: B cells and T cells.
Lymphoid tissue is found in many places throughout the body, including:
- Lymph nodes: bean-sized collections of lymphocytes found in small groups throughout the body, including inside the chest, abdomen, and pelvis. They can sometimes be felt under the skin in the neck, under the arms, and in the groin.
- Thymus: a small organ behind the upper part of the breastbone and in front of the heart. The thymus plays a vital role in development of T cells.
- Spleen: an organ under the lower part of the rib cage on the left side of the body. The spleen makes lymphocytes and other immune system cells to help fight infection. It also stores healthy blood cells and helps filter the blood.
- Tonsils and adenoids: collections of lymphoid tissue at the back of the throat. They help protect the body against germs that are breathed in or swallowed.
- Bone marrow: the soft inner part of certain bones that makes red blood cells, blood platelets, and white blood cells (including lymphocytes).
- Digestive tract: the stomach, intestines, and other organs, which also have lymphoid tissue.
Types of Castleman disease
Doctors can group CD in a number of ways, and they are still trying to determine which classification (or combination of them) provides the most helpful information.
Localized versus multicentric CD
The main way to classify CD is based on how much of the body it affects. The 2 main forms of CD are called localized and multicentric. They affect people very differently.
Localized (unicentric) Castleman disease
This is the more common type of CD. Localized CD only affects a single group of lymph nodes. It is not widespread. Lymph nodes in the chest or abdomen are affected most often. CD causes these lymph nodes to grow.
Enlarged lymph nodes in the chest can press on the windpipe (trachea) or smaller breathing tubes going into the lungs (bronchi), causing breathing problems. If the enlarged nodes are in the abdomen, the person might have pain, a feeling of fullness, or trouble eating. Sometimes the enlarged nodes are in places such as the neck, groin, or underarm area and are first noticed as a lump under the skin.
People with localized CD are usually cured when the affected lymph nodes are removed with surgery.
Multicentric Castleman disease
Multicentric Castleman disease (MCD) affects more than one group of lymph nodes. It can also affect other organs containing lymphoid tissue. This form sometimes occurs in people infected with human immunodeficiency virus (HIV), the virus that causes AIDS. Multicentric CD is more serious than the localized type, particularly in people with HIV infection. You can read more about HIV infection in our document HIV, AIDS, and Cancer.
People with MCD often have problems such as serious infections, fevers, weight loss, fatigue, night sweats, and nerve damage that can cause weakness and numbness. Blood tests often show too few red blood cells (anemia) and high levels of antibodies in the blood (hypergammaglobulinemia).
MCD can weaken the body’s immune system, making it hard to fight infection. Infections in people with MCD can be very serious, even life threatening. MCD also increases the risk of developing lymphoma, a cancer of lymphoid tissue, which can often be hard to treat.
Microscopic subtypes of CD
Castleman disease can also be classified based on how the lymph node tissue looks under a microscope. These are called microscopic subtypes.
- The hyaline vascular type is most common. It tends to be localized, in which case people often have few symptoms and usually have a good outlook, but in rare cases it can be multicentric.
- The plasma cell type is more likely to cause symptoms and to be multicentric, but it is sometimes localized.
- The mixed subtype shows areas of both hyaline vascular and plasma cell types. It occurs less often.
- The plasmablastic type was recognized more recently. Like the plasma cell type, it is usually multicentric, usually causes symptoms, and has a less favorable outlook.
In choosing treatments, doctors believe that the microscopic type is less important than whether the disease is localized or multicentric.
Subtypes of CD based on viral infections
Infection with certain viruses plays a role in at least some cases of CD.
Multicentric CD is more common in people infected with HIV, the virus that causes AIDS. Doctors sometimes group patients with multicentric CD into those who are infected with HIV (HIV positive) and those who are not infected (HIV negative).
In recent years, it’s become clear that another virus, known as human herpesvirus-8 (HHV-8) or Kaposi sarcoma herpesvirus (KSHV), is often found in the lymph node cells of people with multicentric CD. In fact, HHV-8 is found in the lymph nodes of nearly all CD patients who are HIV positive. Some doctors have suggested classifying CD based on whether the cells contain HHV-8.
Last Medical Review: 07/07/2014
Last Revised: 07/07/2014