Castleman Disease

Castleman disease (CD) is a group of rare diseases that affect lymph glands, also called lymph nodes, and lymphatic tissue. Lymph nodes and lymphatic tissue are part of the lymphatic system. This system is part of your body's defense system, also called the immune system.

Lymph nodes are clumps of tissue that filter germs and waste from tissues in your body to your bloodstream. They're found in different places in your body, such as your abdomen, armpits, and groin. CD causes lymph nodes to get bigger from too many cells forming in your lymphatic system.

What are the causes?

• Unicentric CD (UCD). This is the most common type and has fewer symptoms than other types of CD.
  • CD affects only one lymph node or only one group of lymph nodes, usually in your chest or abdomen.
  • The cause of UCD isn't known. But it's thought to be caused by a gene change, called a mutation, in the white blood cells.
• Multicentric CD (MCD). This type affects several groups of lymph nodes. It may cause more symptoms and may be harder to treat.
  • MCD isn't cancer, but it may act like cancer. It may also improve with cancer treatments such as chemotherapy.
  • MCD may come back after treatment. It may also turn into lymphoma. This is a type of cancer of the white blood cells.

• HHV-8-associated MCD. This is caused by a type of human herpesvirus (HHV-8). People can be at higher risk of this type of MCD if:
  • They have HIV or AIDS. HIV makes the body less able to fight HHV-8 infection.
  • They have weak immune systems from another cause.
• HHV-8 neg-associated MCD, also called idiopathic MCD. The cause of this isn't known.
• POEMS-associated MCD. This is caused by cancer cells found in people with POEMS syndrome.
  • POEMS syndrome is also called polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, and skin changes.
  • In some people who are HHV-8 negative, POEMS syndrome can cause MCD. It can also cause the body to make extra cytokines. These are proteins.

What increases the risk?

The only known risk for CD is HIV infection. HIV weakens the body's immune system. This makes you more likely to get infections like 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 one or more lymph nodes getting bigger in one area of your body.

People with MCD are more likely to have symptoms. You may see or feel bigger lymph nodes in more than one area of your body. A physical exam may show that your liver or spleen has gotten bigger.

• Fever or night sweats.
• Nausea, vomiting, or weight loss.
• Extra large lymph nodes, often in or near the neck, armpit, collarbone, and groin.
• Skin rash.
• Swollen legs.
• Pain or fullness in your abdomen.
• Tiredness, numbness, or weakness.
• Shortness of breath.

How is this diagnosed?

• Your symptoms and medical history.
• A physical exam.
• Biopsy of one or more large lymph nodes. For this, the nodes are removed so their cells can be tested.
• Imaging tests of your abdomen and chest to check lymph nodes that aren't near the skin. These tests may include CT scan, MRI, and ultrasound.
• Blood tests to check for:
  • HHV-8 virus.
  • Signs of idiopathic MCD. These include blood markers that show inflammation, anemia, abnormal platelets, low protein, or kidney problems.

How is this treated?

• UCD is usually treated with surgery to remove the swollen lymph nodes. It's rare for UCD to come back after surgery.
  • Sometimes swollen lymph nodes are close to major blood vessels or deep inside a lung. If yours are, you may need treatment with medicines or radiation. Treatment can shrink the lymph node or tumor before you have surgery.
• 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 doesn't work, you may be given:
  • Different medicines that lower the activity of the immune system. These are called immunosuppressants.
  • Chemotherapy medicines.
• If you have POEMS-associated MCD, treatment will target the POEMS syndrome.

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 provider about possible side effects.
• Return to your normal activities as told by your provider. Ask your provider what activities are safe for you.
• Keep all follow-up and checkup visits. You'll need regular checkups 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.
• Your arms or legs are swollen.
• You get any new symptoms.
• Symptoms of CD come back after treatment.

Get help right away if:

• You have trouble breathing.