What is Castleman disease?
Castleman disease (CD) is a rare condition that affects your lymph nodes and related tissues. The disease occurs when there’s an overgrowth of cells in your lymphatic system. The lymphatic system is part of your immune system. It rids your body of toxins and other waste in order to fight infections and keep you healthy.
About 200 new cases are diagnosed in the United States every year.
Unicentric Castleman disease is the most common form. It happens when only one lymph node region is affected. Multicentric Castleman disease develops when more than one lymph node region is affected. It can also affect other organs containing lymphoid tissue.
Although a similar cell growth process occurs with lymphomas, or cancers of the lymph nodes, Castleman disease isn’t a form of cancer. However, people who have multicentric Castleman disease are more likely to develop lymphoma and other blood cancers later on.
Keep reading to learn about what causes Castleman disease, treatment options, and more.
What are the symptoms of Castleman disease?
Unicentric Castleman disease
Unicentric Castleman disease usually affects the lymph nodes in your chest or abdomen. Castleman disease can cause these nodes to grow. Unicentric Castleman disease typically doesn’t cause any symptoms unless your lymph nodes become large enough to interfere with other organs.
If the nodes in your chest are enlarged, you may have difficulty breathing.
If the nodes in your abdomen are enlarged, you may experience:
- feelings of fullness
- difficulty eating
In some cases, you might notice a lump under the skin in your neck, groin, or armpit.
Multicentric Castleman disease
This form of Castleman disease is more serious, because it affects more than one group of lymph nodes. It can also cause the enlargement of certain organs, such as your liver and spleen.
Other symptoms include:
- weight loss
- night sweats
- general weakness or numbness
People who have multicentric Castleman disease are also more prone to serious infections and anemia.
What causes Castleman disease?
The exact cause of Castleman disease isn’t clear.
The disease is characterized by an overgrowth of both B cells and plasma cells, which are immune system cells called lymphocytes. Scientists don’t know exactly why the immune system malfunctions.
However, there appears to be a strong association between multicentric Castleman disease and an infection caused by human herpesvirus 8 (HHV-8). HHV-8 is often found in the lymph nodes of people who have both multicentric Castleman disease and HIV.
The HHV-8 virus is also linked to Kaposi sarcoma, a cancerous tumor that forms in blood vessel walls. Kaposi’s sarcoma may develop as a complication of HIV or AIDs.
HHV-8 isn’t present in all multicentric Castleman disease cases. Additionally, unicentric Castleman disease doesn’t have a strong association with any particular virus. Researchers have yet to establish what causes Castleman disease in people without HHV-8.
Who’s at risk?
Unicentric Castleman disease is much more common than multicentric. Unicentric Castleman disease may affect both children and adults. On average, a unicentric diagnosis is made by age 35. This form tends to be more common in women.
Multicentric Castleman disease primarily develops in adults in their 50s and 60s. Men are slightly more likely than women to develop this form of the disease.
Overall, people who have HIV or AIDs are most at risk for developing either type of Castleman disease.
Diagnosing Castleman disease
In many cases, a diseased or enlarged lymph node will go undetected until you’re being treated for another illness.
But if you’re experiencing symptoms, see your doctor. They will assess the size and consistency of your lymph nodes.
From there, your doctor may order one or more of the following:
- Blood and urine tests: These can help rule out other infections, as well as determine if there are any abnormalities that may signify Castleman disease.
- Imaging tests: A CT scan or MRI scan can reveal enlarged lymph nodes in your neck, chest, abdomen, or pelvis. They can also determine whether your liver or spleen is enlarged. A PET scan may also be used.
- Biopsy: Your doctor may remove a small piece of tissue from the affected node or organ to test.
What treatment options are available?
Treatment for Castleman disease will depend on the type you have.
Because unicentric Castleman disease is localized, it can usually be cured by surgically removing the diseased lymph node. This surgery may be minor or more extensive depending on the node’s location.
If the node is in a location that can’t be removed surgically, or if you’re otherwise ineligible for operation, you may be given a medication to help shrink the lymph node. In some cases, radiation therapy may be used to destroy the diseased tissue.
Surgery isn’t an option for multicentric Castleman disease because it affects multiple parts of the body. Instead, treatment focuses on managing the cell overgrowth through medication or other therapies.
You may be prescribed one or more of the following:
- monoclonal antibodies, such as rituximab (Rituxan) or siltuximab (Sylvant), to help stop cell overgrowth
- chemotherapy, which may also help reduce cell growth
- corticosteroids, such as prednisone (Deltasone), to reduce inflammation
- thalidomide (Thalomid), an oral cancer drug that may help induce remission for Castleman disease
- antiviral therapy to fight HHV-8 or HIV
Your individual outlook will depend on the type of Castleman disease you’re diagnosed with and any other underlying conditions you may have.
Unicentric Castleman disease can often be treated successfully with surgery. You will, however, have to go to frequent follow-up exams to ensure the disease hasn’t come back. When this happens, it’s called recurrence. If you experience any symptoms, it’s important to report them to your doctor as soon as possible.
Multicentric Castleman disease can be more challenging, often because the disease occurs alongside HIV or AIDS. Even if Castleman disease is treated successfully, the disease sometimes returns within a year. Follow-up care is especially important, because this condition can lead to non-Hodgkin’s lymphoma, a potentially life-threatening form of cancer. It’s also associated with other blood system cancers including Kaposi sarcoma.
Can Castleman disease be prevented?
It isn’t clear whether Castleman disease can be prevented, because it isn’t clear what exactly causes Castleman disease. The one thing you can do to reduce your risk for Castleman disease is to protect yourself against HIV infection.
Practicing safe sex by using condoms and dental dams can significantly reduce your risk for HIV. Getting testing regularly for sexually transmitted infections, including HIV, will increase the chances that you receive early treatment for any infection. You should also ensure that any sexual partner you have has been tested as well.