Castleman disease is diagnosed in some 4,300 to 5,200 people each year in the U.S. The two primary types are unicentric Castleman disease and multicentric Castleman disease. The condition affects your lymph system and causes symptoms similar to the flu.
Castleman disease refers to a group of rare disorders that involve a hyperactive immune system. In people who are healthy, their immune system activates to fight off invaders like bacteria or viruses but then settles back down, watching and waiting for the next time it’s needed. In people with Castleman disease, their immune system continues to remain activated and leads to a chronic hyper-inflammatory state that can damage multiple organs and even cause death.
Lymph nodes (tiny organs) work with your immune system to filter substances from your body. When you’re sick, your lymph nodes work harder to clear the bacteria or virus, along with the cells your body makes to fight them. This causes an overgrowth of cells in your lymph nodes, making these nodes bigger (swell).
In Castleman disease, one or more of your lymph nodes become enlarged. And they don’t just get bigger. When your doctor looks at a sample of your lymph node (a biopsy) under a microscope or analyzes them using different staining, they can see changes in the tissue.
Castleman disease is currently classified as unicentric or multicentric based on how many regions of your body have enlarged lymph nodes. The differences between unicentric and multicentric Castleman disease are important because each type requires different treatments.
Unicentric Castleman disease (UCD) — or localized Castleman disease — causes enlargement of one or more lymph nodes in one area (region) of your body. The causes of UCD are unknown.
Multicentric Castleman disease (MCD) causes lymph node enlargement in multiple regions of your body. There are three categories of MCD: POEMS-associated MCD, HHV-8-associated MCD and idiopathic MCD.
There are three types of iMCD:
Research on Castleman disease is ongoing. Certain autoimmune conditions, cancers or infections can present with changes in lymph nodes or clinical features that closely resemble Castleman disease. It’s unknown whether Castleman disease should be considered an autoimmune disease, cancer or infectious disease.
Castleman disease can affect anyone. UCD is more commonly diagnosed in people in their 30s and 40s. MCD is more common in people in their 50s and 60s. While UCD affects people equally regardless of sex, MCD is slightly more common in men and people assigned male at birth (AMAB).
Castleman disease is rare, with approximately 4,300 to 5,200 new cases diagnosed in the United States each year. About 75% of these cases are UCD, and the remaining 25% are MCD.
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While the causes of UCD are unknown, an HHV-8 infection is associated with MCD. You’re at greater risk of developing HHV-8-associated MCD if you have HIV or another condition that may make it difficult for your immune system to fight the HHV-8 virus.
Scientists are researching potential causes of UCD and iMCD, including infections other than HHV-8, gene mutations and autoimmune responses.
Signs and symptoms of Castleman disease vary depending on the type. For example, you likely won’t have symptoms with unicentric Castleman disease, and enlarged lymph nodes may be the only sign. Your healthcare provider may not suspect UCD until they notice lymph node enlargement during imaging for another issue. When symptoms occur, they may result from an enlarged lymph node creating pressure on a nearby organ.
MCD is much more likely to cause noticeable changes.
Signs and symptoms of MCD include:
Castleman disease symptoms are similar to other conditions, including common illnesses like the flu. Your healthcare provider may perform various tests to rule out these conditions. They’ll perform additional tests to determine the type of Castleman disease.
Tests and procedures may include:
Treatment for Castleman disease varies according to the type.
Surgery to remove the affected lymph nodes is the primary treatment for UCD. Depending on where the lymph nodes are located or if they’re too big, you may need to receive radiation therapy or immunotherapy before surgery for UCD. These therapies shrink the growths on your lymph nodes, making them easier to remove.
If surgeons can’t remove the tumor and you don’t have symptoms, your provider may prefer to monitor your tumor instead of treating it immediately. If surgery isn’t an option and you have symptoms, your provider may recommend treatments for multicentric Castleman disease.
MCD is more difficult to treat than UCD. Because the multicentric type is widespread, healthcare providers don’t typically use surgery or radiation to treat it. Instead, treatment depends on whether you have HHV-8 and how severe the disease is.
Your provider may use:
Castleman disease increases your chances of developing cancer, including lymphoma (cancer of the lymph system).
MCD can increase your risk of developing infections that can damage organs and even be life-threatening without treatment.
Your healthcare provider will closely monitor your condition, tailoring your treatment to prevent complications whenever possible.
There aren’t any known risk factors for UCD or iMCD. People with the human immunodeficiency virus (HIV) or a weakened immune system are at higher risk of developing HHV-8-associated MCD.
There aren’t any known risk factors for most types of Castleman disease, so there’s nothing you can do to prevent them.
The outlook is very good for most people with UCD. Removing the affected lymph node is often enough to cure it. With treatment, UCD doesn’t usually affect life expectancy.
The prognosis for people with MCD depends on the type of MCD and how serious the disease is. Some people have intense flares that can be life-threatening. Others have more chronic symptoms. About 65% to 75% of people diagnosed with MCD are still alive five years later — and with breakthrough therapies, there’s hope that the outlook will continue to improve.
Talk to your provider about how your form of Castleman disease and other factors like another disease or condition may impact your outlook.
Contact your healthcare provider if you find a lump in your neck, armpit or groin or experience other symptoms of Castleman disease that don’t go away after a few weeks. Symptoms of Castleman disease often overlap with symptoms of other, more common illnesses. Your doctor will only diagnose it after a lymph node biopsy shows features of Castleman disease and evaluates and excludes other illnesses that might be causing your symptoms.
Questions you should ask your healthcare provider include:
A note from Cleveland Clinic
Castleman disease causes abnormal growths in your lymph system. Your symptoms and treatment options depend on the type of Castleman disease you have. Additional conditions like HIV or associated disorders — like TAFRO and POEMS — will also shape your experience. In some instances, surgery and careful monitoring may be the only treatment you need. Or you may need a combination of treatments throughout your lifetime to prevent the risk of significant complications. Ask your healthcare provider how your condition will impact your treatment and outlook.
Last reviewed by a Cleveland Clinic medical professional on 09/30/2022.
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