Castleman Disease

Castleman disease is a group of rare disorders that involves lymph nodes that get bigger, called enlarged lymph nodes, and a wide range of symptoms. The most common form of the disorder involves a single enlarged lymph node. This lymph node is usually in the chest or neck, but it can occur in other areas of the body as well. This form of the disorder is called unicentric Castleman disease (UCD).

Multicentric Castleman disease (MCD) involves multiple regions of enlarged lymph nodes, inflammatory symptoms and problems with organ function. There are three types of MCD:

• HHV-8-associated MCD. This type is linked to human herpes virus type 8, called HHV-8, and human immunodeficiency virus (HIV).
• Idiopathic MCD. The cause of this type is unknown. This also is called HHV-8-negative MCD.

  The most serious form of this type of MCD is known as iMCD-TAFRO. This condition gets its name from the symptoms it causes.

• POEMS-associated MCD. This type is linked to another condition called POEMS syndrome. POEMS syndrome is a rare blood disorder that damages nerves and affects other parts of the body.

Sometimes, people may have 2-3 enlarged lymph nodes and mild symptoms that do not meet the diagnostic criteria for MCD. These people may have another disease, or they may have the recently described subtype of Castleman disease called oligocentric Castleman disease. This subtype is rare.

Treatment and outlook vary depending on the type of Castleman disease you have. Unicentric Castleman disease, which is the type that involves only one enlarged lymph node, can usually be successfully treated with surgery.

The best treatment for oligocentric Castleman disease, which involves a few enlarged lymph nodes and has limited symptoms, is not known but is thought to be similar to the treatment for unicentric Castleman disease.

While not all people with MCD respond to the first treatment, there are medicines that work to treat HHV-8-associated MCD and idiopathic MCD.