Castleman Disease

Castleman disease (CD) refers to a group of rare diseases that affect lymph nodes and lymphatic tissue. The lymphatic system helps your body fight germs by filtering bacteria, viruses, and waste from the bloodstream. It is part of the body's disease-fighting system (immune system).

Lymph nodes are tissues that filter germs and waste from your blood. They are found in various places in your body, including the abdomen, underarms, and groin.

CD causes enlargement of lymph nodes due to abnormal overgrowth of cells in the lymphatic system.

What are the causes?

The cause of CD depends on which type you have. There are three types of CD:

Unicentric CD (UCD). This is the most common type. It affects only one lymph node or only one group of lymph nodes, usually in the chest or abdomen. It causes fewer symptoms than other types of CD. The cause of UCD is not known. It may be caused by a change, or mutation, in the genes of white blood cells.
Multicentric CD (MCD). This type affects several groups of lymph nodes. It may cause more symptoms and be harder to treat. MCD is not cancer, but it may act like cancer and respond to cancer treatments such as chemotherapy. MCD may come back after treatment, and it may turn into a type of white blood cell cancer (lymphoma). There are two kinds of MCD:
- HHV-8-associated MCD. This is caused by a type of human herpes virus (HHV-8). People with HIV or AIDS are at higher risk for this type of MCD because HIV lowers the body's ability to fight HHV-8 infection.
- HHV-8 neg-associated MCD, also called idiopathic MCD. The cause of this is not known.

What increases the risk?

The only known risk factor for CD is HIV infection. HIV weakens the body's immune system, which makes a person more likely to get infections like the human herpes virus (HHV-8).

What are the signs or symptoms?

Symptoms of CD depend on the type. If you have UCD, you may have no symptoms, or your only symptom may be enlargement of one or more lymph nodes in one area of your body.

People with MCD are more likely to have symptoms. You may see or feel enlarged lymph nodes in more than one area of your body. A physical exam may show enlargement of your liver or spleen. The following symptoms are more common with MCD, but they are possible for all types of CD:

Fever or night sweats.
Nausea, vomiting, or weight loss.
Skin rash.
Swelling in the legs.
Abdominal pain or fullness.
Tiredness, numbness, or weakness.
Shortness of breath.

How is this diagnosed?

This condition may be diagnosed based on:

Your symptoms. Your health care provider may suspect CD if you have an enlarged lymph node.
A physical exam.
Removal of one or more enlarged lymph nodes to examine its cells under a microscope (biopsy).
Imaging tests of your abdomen and chest to check lymph nodes that are not near the skin. These tests may include CT scan, MRI, and ultrasound.
Blood tests to check for:
- HHV-8 virus.
- Signs of idiopathic MCD, such as blood markers that show inflammation, anemia, platelet abnormalities, low protein, or kidney dysfunction.

How is this treated?

Treatment depends on the type of CD you have:

UCD is usually treated with surgery to remove the affected lymph nodes. It is rare for UCD to come back after surgery.
- If affected lymph nodes are close to major blood vessels or deep inside a lung, you may need treatment to reduce the size of the lymph node or tumor before you have surgery. This treatment uses medicines and radiation to reduce the size of the lymph node or tumor.
HHV-8-associated MCD is usually treated with medicine to boost your immune system. This is called immunotherapy. You may also be given steroids.
- If the disease comes back after treatment, you may need another round of immunotherapy.
- Many people with HHV-8-associated MCD also have HIV or AIDS. Treating HIV or AIDS also helps to control HHV-8-associated MCD.
Idiopathic MCD is treated with immunotherapy. If immunotherapy does not work, you may be given:
- A variety of medicines that reduce the activity of the immune system (immunosuppressants).
- Chemotherapy medicines.

Follow these instructions at home:

Take over-the-counter and prescription medicines only as told by your health care provider.
If you take medicine or are having radiation for CD, make sure you talk with your health care provider about possible side effects.
Return to your normal activities as told by your health care provider. Ask your health care provider what activities are safe for you.
Keep all follow-up and checkup visits. It is important to have checkups on a regular basis for about 5 years to make sure CD does not come back. Checkups may include a physical exam, lab tests, and imaging tests.

Where to find more information

National Organization for Rare Disorders: rarediseases.org

Contact a health care provider if:

You have chills or a fever.
You have swelling in your arms or legs.
You develop any new symptoms.
Symptoms of CD come back after treatment.

Get help right away if:

You have trouble breathing.

These symptoms may represent a serious problem that is an emergency. Do not wait to see if the symptoms will go away. Get medical help right away. Call your local emergency services (911 in the U.S.). Do not drive yourself to the hospital.

Summary

Castleman disease (CD) is a group of diseases that affect lymph nodes and lymphatic tissue.
Signs and symptoms of CD depend on the type.
UCD is the most common type of CD. It causes fewer symptoms, and it may be cured with surgery.
MCD is more serious and harder to treat. Treatment may include several types of medicines.
After being treated for CD, it is important to have checkups regularly to make sure the disease does not come back.