Castleman disease is a rare disorder that involves an overgrowth (proliferation) of cells in your body's disease-fighting network (lymphatic system). Also known as giant lymph node hyperplasia and angiofollicular lymph node hyperplasia, Castleman disease can occur in a localized (unicentric) or widespread (multicentric) form.

Treatment and outlook vary, depending on the type of Castleman disease you have. The localized type can usually be successfully treated with surgery.

Sometimes associated with HIV infection, multicentric Castleman disease can be life-threatening. Multicentric Castleman disease is also associated with other cell-proliferation disorders, including cancer of the lymphatic system (lymphoma), Kaposi's sarcoma and POEMS syndrome.

There are two basic types of Castleman disease:

  • Unicentric Castleman disease. This localized form of the disease affects only a single gland (lymph node) in your lymphatic system.
  • Multicentric Castleman disease. This type affects multiple lymph nodes and lymphatic tissues, and can severely weaken your immune system.

Multicentric Castleman disease can be further classified as:

  • Multicentric Castleman disease without POEMS syndrome
  • Multicentric Castleman disease with POEMS syndrome that involves areas of abnormal bone (osteosclerotic lesions)
  • Multicentric Castleman disease with POEMS syndrome without osteosclerotic lesions

Unicentric Castleman disease

Many people with unicentric Castleman disease don't notice any signs or symptoms. The diseased lymph node is usually located in the chest, neck or abdomen. When signs and symptoms are present, they may include:

  • A feeling of fullness or pressure in the chest or abdomen that can cause difficulty breathing or eating
  • An enlarged lump under the skin in the neck, groin or armpit
  • Unintended weight loss
  • Less commonly, fever, night sweats and weakness

Multicentric Castleman disease

Most people with multicentric Castleman disease experience:

  • Fever
  • Night sweats
  • Fatigue and weakness
  • Loss of appetite
  • Unintended weight loss
  • Enlarged lymph nodes, usually around the neck, collarbone, underarm and groin areas
  • Enlarged liver or spleen

Other, less common symptoms include:

  • Nerve damage in the hands and feet that leads to numbness (peripheral neuropathy)
  • Skin rash

When to see a doctor

If you notice an enlarged lymph node on the side of your neck or in your underarm, collarbone or groin area, talk to your doctor. Also call your doctor if you experience a persistent feeling of fullness in your chest or abdomen, fever, fatigue, or unexplained weight loss.

It's not clear what causes Castleman disease. However, infection by a virus called human herpesvirus 8 (HHV-8) is associated with multicentric Castleman disease.

The HHV-8 virus has also been linked to the development of Kaposi's sarcoma, a cancerous tumor of the blood vessel walls that can be a complication of HIV/AIDS. Studies have found that HHV-8 is present in HIV-positive people who have Castleman disease, and in 40 to 50 percent of HIV-negative people with Castleman disease.

The precise role of HHV-8 is unclear. But it appears to cause malfunctioning immune system cells to reproduce rapidly. The immune system cells produce a protein called interleukin-6 (IL-6) that contributes to the overgrowth of lymphatic cells.

Castleman disease can affect anyone. But the average age of people diagnosed with unicentric Castleman disease is 35. Most people with the multicentric form are in their 50s and 60s. The multicentric form is also slightly more common in men than in women.

The only known risk factor for Castleman disease appears to be having HIV/AIDS.

People with unicentric Castleman disease usually do well once the affected lymph node is removed. However, having Castleman disease may increase your risk of lymphoma.

Complications of multicentric Castleman disease can be life-threatening and may include:

  • Infection leading to the failure of multiple organs
  • Cancer, such as lymphoma or Kaposi's sarcoma

The outlook for people with multicentric Castleman disease varies, depending on the nature of their disease. The presence of HIV/AIDS tends to worsen the outcome.

Research also indicates that people who have multicentric Castleman disease with POEMS syndrome that doesn't involve bone lesions may have worse outcomes, while people who have multicentric Castleman disease with the bone lesion variant of POEMS syndrome tend to do better.

You may be referred to a doctor who specializes in treating blood disorders (hematologist).

What you can do

  • Write down the symptoms you have been experiencing and for how long.
  • Write down key medical information, including other conditions.
  • Make a list of all medications, vitamins and supplements that you're taking.

Questions to ask your doctor

  • What's the most likely cause of my signs and symptoms?
  • What kinds of tests do I need? Do they require any special preparation?
  • What treatment do you recommend? Do I need surgery?

In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask other questions during your appointment.

What to expect from your doctor

Your doctor is likely to ask you a number of questions. Being ready to answer them may make time to go over points you want to spend more time on. You may be asked:

  • Do you have any other health conditions, such as HIV/AIDS or Kaposi's sarcoma?
  • When did you first begin experiencing symptoms?
  • Have your symptoms been continuous or occasional?
  • How severe are your symptoms?
  • Does anything seem to improve your symptoms?
  • What, if anything, appears to worsen your symptoms?

People with unicentric Castleman disease often notice no signs or symptoms. The diseased lymph node may be found during screening or treatment for another illness.

If unicentric or multicentric Castleman disease is suspected, your doctor is likely to start with a thorough physical examination of your lymph nodes, to determine their size and consistency.

Your doctor may then recommend:

  • Blood and urine tests, to help rule out other infections or diseases. These tests can also reveal anemia and abnormalities in blood proteins that are sometimes characteristic of Castleman disease.
  • Imaging tests, to detect enlarged lymph nodes, liver or spleen. CT scan or MRI of your neck, chest, abdomen and pelvis may be used. Positron emission tomography (PET) scans also may be used to diagnose Castleman disease and to assess whether a treatment is effective.
  • Lymph node biopsy, to differentiate Castleman disease from other types of lymphatic tissue disorders, such as lymphoma. A tissue sample from an enlarged lymph node is removed and examined in the laboratory. Depending on the location of the lymph node, the biopsy may be done under local anesthesia or during more extensive surgery.

Treatment depends on the type of Castleman disease you have.

Unicentric Castleman disease

Unicentric Castleman disease can be cured by surgically removing the diseased lymph node. If the lymph node is in your chest or abdomen — which is often the case — major surgery may be required.

If surgical removal isn't possible, medication may be used to shrink the lymph node. Radiation therapy also may be an effective way to destroy the affected tissue.

You'll need follow-up exams, including imaging, to check for relapse.

Multicentric Castleman disease

Surgery usually isn't an option for multicentric Castleman disease because of the number of lymph nodes involved. However, surgery to remove an enlarged spleen may be an option to help ease symptoms.

Treatment generally involves medications and other therapies to control cell overgrowth. Specific treatment depends on the extent of your disease and on whether you have HIV or HHV-8 infection or both.

The options include:

  • Monoclonoal antibodies, to block the action of the IL-6 protein that contributes to cell overgrowth. Your doctor may recommend initial treatment with a monoclonal antibody, such as siltuximab (Sylvant), if you don't have organ damage or HIV or HHV-8 infection.
  • Chemotherapy, to slow overgrowth of lymphatic cells. Your doctor may recommend adding chemotherapy if the disease doesn't respond to monoclonal antibodies or if you have organ failure.
  • Corticosteroids, to control inflammation.
  • Antiviral drugs, to block the activity of HHV-8 or HIV if you have one or both of those viruses.
  • Thalidomide (Thalomid), to block the action of the IL-6 protein. Thalidomide is an immune-system modulator that has been shown to be effective at inducing remission in Castleman disease.

A diagnosis of Castleman disease can be challenging because the condition is rare and often occurs with other serious illnesses, such as HIV/AIDS and Kaposi's sarcoma. To help you cope with Castleman disease:

  • Find someone to talk with. You may feel comfortable discussing your feelings with a friend or family member, or you might prefer meeting with a formal support group.
  • Set reasonable goals. Having goals helps you feel in control and can give you a sense of purpose. But choose goals that you can reach.
Aug. 27, 2014