Castleman Disease

DEFINITION

Castleman disease is a rare illness that causes overgrowth of the lymph nodes, structures that normally serve as a signal center for the immune system. Normally, a white blood cell catches a bacteria, virus, or mold in the body then carries it to the lymph node where the other white blood cells send out a cascade of signals to the body to get the infection under control. In Castleman disease, the lymph cells grow too rapidly. While Castleman disease is not a cancer, it is similar to cancers like lymphoma that also cause an overgrowth of these cells. Castleman disease can either occur at a single location (unicentric) or multiple locations (multicentric). The cause of Castleman disease is not yet known. Certain factors are thought to play a part like human herpes virus 8 (HHV8) in multicentric Castleman disease. The only known risk factor for Castleman disease is having HIV, though many people with Castleman disease do not have HIV. If you have only one lymph node with Castleman disease, it is possible to remove that lymph node with few associated problems (though you will have a slightly increased risk of future lymphoma). Multicentric Castleman disease is a different story. This disease is much more severe and can be life-threatening especially if you get infection or another cancer.

SYMPTOMS
Fever, infection, rash on the skin, difficulty breathing, weight loss, sweating, low blood counts, nausea and vomiting, loss of appetite, night sweats, enlarged lymph nodes, enlarged liver, enlarged spleen, pain in the hands and feet from peripheral neuropathy

DIAGNOSIS
Your doctor will begin by talking to you about your symptoms and doing a physical exam. Your doctor will pay special attention to any enlarged lymph nodes. Your doctor may recommend certain blood tests to look for infection as an alternate cause of your enlarged lymph nodes a well as to look for low blood counts that are common in Castleman disease. Your doctor may recommend taking some pictures of your body to look for enlarged lymph nodes including X-ray, computerized tomography scan (CT scan) or magnetic resonance imaging (MRI) . If your doctor finds an abnormal lymph node, he or she may recommend taking a small piece of that node to examine under a microscope (biopsy). Lymph node biopsy can help to differentiate Castleman disease from lymphoma.

TREATMENT
Treatment for Castleman disease depends whether you have unicentric or multicentric Castleman disease. Unicentric Castleman disease is usually treated with removal of the abnormal lymph node with surgery. In some cases, this may cure the Castleman disease. The removal of the lymph node may be simple if the lymph node is in an accessible location. However, if the abnormal lymph node is somewhere like the abdomen, getting it out may involve a larger surgery. Radiation of the lymph node may be an alternate therapy if surgery is not an option. For multicentric Castleman disease, the best type of treatment is not clear because the disease is rare and the course of the disease is unpredictable. Generally, surgery does not help for multicentric disease but the spleen may be taken out if it is enlarged to help relieve symptoms. Your doctor may recommend medications to help relieve your symptoms including steroids (which help reduce inflammation at the lymph nodes), chemotherapy or medications that fight cancer (though people have the same side effects as with cancer: weight loss, hair loss, nausea and vomiting, loss of appetite), antiviral medications (some mixed success has been shown with medications that fight HHV8), monoclonal antibodies (antibodies that fight abnormal activity by the body), and immune modulators (which have only been successful in a few people). You should discuss your treatment options with your doctor.