Castleman Disease

What is Castleman disease?

Castleman disease (also called Castleman’s disease, giant lymph node hyperplasia or Castleman tumor) is a rare disorder that comes in two forms. Both forms cause abnormal cell growth, creating non-cancerous tumors and lymph node enlargement that affect the disease-fighting lymphatic system. However, in unicentric Castleman disease, there is only one solid growth localized in a solitary lymph node. The more lethal form of Castleman disease (multicentric) occurs when these growths are widespread. Because people with Castleman disease are often asymptomatic or exhibit common symptoms like fatigue, weight loss, and fever, Castleman is easily misdiagnosed as other associated lymphatic disorders. That’s why it’s key to be aware of Castleman’s most recognizable symptom: an enlargement in the armpit, neck, collarbone, or around the groin. Finding that lump under the skin is the best chance for a proper diagnosis, and with a diagnosis, patients can largely mitigate the effects of the condition with surgery or treatment.

How common is Castleman Disease?

Unicentric and multicentric Castleman can affect men and women of any age, though children are less likely to develop it. About 30,000 people in the U.S. are currently diagnosed with the disorder.

What causes Castleman Disease?

Castleman’s cause is unknown. Overproduction of the protein interleukin-6 (IL-6), which is found within the lymph nodes and helps organize the body’s immune response to infection, may play a role in causing cell overgrowth. Speculation suggests this malfunction could be influenced by the human herpesvirus 8 (HHV-8). Almost everyone with the human immunodeficiency virus (HIV) has HHV-8, but even without HIV, 40-50% of people with multicentric Castleman disease have HHV-8. The how’s and why’s linking IL-6, HHV-6, and Castleman remain undetermined.

What are the symptoms of Castleman disease?

Symptom prevalence varies between the two types of Castleman disease:

• Unicentric: Often asymptomatic with the disease localized in the neck, abdominal region, or chest. If symptoms exist, they may include pressure in the chest or stomach, unexplained weight loss, and a lump located near the groin, neck, or underarm.
• Multicentric: Usually not asymptomatic, symptoms of multicentric Castleman disease include those found in its counterpart, as well as an enlargement of the spleen or liver, night sweats, fever, weakness, skin rash, or nerve damage in the limbs. Left untreated, this form of Castleman disease may lead to a co-morbidity, like lymphoma or infection, and cause organ failure and death.

How do people inherit Castleman Disease?

As of now, it’s unclear what—if any—genetic link exists for Castleman disease. However, those with associated conditions, such as HIV, malignant lymphoma, Kaposi’s sarcoma, or POEMS syndrome, should be extra cautious.

Where can I find more information about Castleman Disease?

• Castleman Disease Collaborative Network
• National Organization for Rare Diseases (NORD)
• Mayo Clinic