What is Castleman Disease?
Castleman disease (CD) is a rare disease of lymph nodes and related tissues. It was first described by Dr. Benjamin Castleman in the 1950s. It is also known as Castleman’s disease, giant lymph node hyperplasia, and angiofollicular lymph node hyperplasia (AFH).
Castleman disease is not cancer. Instead, it is called a lymphoproliferative disorder. This means there is an abnormal overgrowth of cells of the lymphatic system that is similar in many ways to lymphomas (cancers of lymph nodes).
Even though CD is not officially cancer, one form of this disease (known as Multicentric Castleman Disease) acts very much like lymphoma. In fact, many people with this disease eventually develop lymphomas. And like lymphoma, CD is often treated with chemotherapy or radiation therapy. This is why it is included in the American Cancer Society’s cancer information.
Castleman disease is first classified based on the number of regions of enlarged lymph nodes that demonstrate these abnormal features. Unicentric Castleman Disease (UCD) involves a single enlarged lymph node or a single region of enlarged lymph nodes whereas Multicentric Castleman Disease (MCD) involves multiple regions of enlarged lymph nodes.
There are two sub-types of MCD. A subset of MCD is caused by human herpesvirus-8 (HHV-8; also known as Kaposi sarcoma-associated herpesvirus). These cases are called HHV-8-associated MCD. There are also MCD patients who are negative for the HHV-8 virus, and the cause is unknown. These cases are called HHV-8 negative or “idiopathic” MCD (iMCD). Castleman disease can also be described as hyaline-vascular, plasmacytic, mixed, and plasmablastic. based on the microscopic appearance. The usefulness of this sub-typing is unclear.
Castleman Disease Causes:
It’s not clear what causes Castleman disease. However, infection by a virus called human herpesvirus 8 (HHV-8) is associated with multicentric Castleman disease.
The HHV-8 virus has also been linked to the development of Kaposi’s sarcoma, a cancerous tumor that can be a complication of HIV/AIDS. Studies have found that HHV-8 is present in nearly all HIV-positive people who have Castleman disease, and in about half of HIV-negative people with Castleman disease.
If a patient has multiple regions of enlarged lymph nodes with CD features identified by a pathologist under the microscope AND is HIV-negative and his/her lymph node and blood sample are HHV-8-negative, he/she may have HHV-8-negative or idiopathic MCD (iMCD).
Castleman disease can affect people of any age. But the average age of people diagnosed with unicentric Castleman disease is 35. Most people with the multicentric form are in their 50s and 60s. The multicentric form is also slightly more common in men than in women.
The risk of developing multicentric Castleman disease is higher in people who are infected with HHV-8 virus.
Castleman Disease Signs & Symptoms:
Many people with unicentric Castleman disease don’t notice any signs or symptoms. The enlarged lymph node may be detected during a physical exam or an imaging test for some unrelated problem.
Some people with unicentric Castleman disease might experience signs and symptoms more common to multicentric Castleman disease, which may include:
- Unintended weight loss
- Night Sweats
- Enlarged liver or spleen
The enlarged lymph nodes associated with multicentric Castleman disease are most commonly located in the neck, collarbone, underarm and groin areas.
IMCD involves multicentric lymphadenopathy with characteristic “CD-like” lymph node histopathology and a number of signs and symptoms as defined by the 2017 International Consensus Diagnostic Criteria of iMCD, which may progress or remit/relapse over time:
- Elevated C-reactive protein (CRP) level and/or erythrocyte sedimentation rate (ESR)
- Thrombocytopenia or thrombocytosis
- Renal dysfunction and/or proteinuria
- Polyclonal hypergammaglobulinemia
- Flulike symptoms (night sweats, fever, weight loss, fatigue)
- Large liver and/or spleen
- Fluid accumulation (edema, anasarca, ascites, pleural effusion)
- Eruptive cherry hemangiomatosis or violaceous papules
- Lymphocytic interstitial pneumonitis
What Is Castleman Disease? https://www.cancer.org/cancer/castleman-disease/about/what-is-castleman-disease.html
David Fajgenbaum, MD, MBA, MSc. Castleman disease. National Organization for Rare Disorders (NORD). https://rarediseases.org/rare-diseases/castlemans-disease/
Castleman disease – Symptoms and causes. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/castleman-disease/symptoms-causes/syc-20370735
About Castleman Disease. Castleman Disease Collaborative Network. https://www.cdcn.org/about-castleman-disease
Neetu Radhakrishnan, MD. https://emedicine.medscape.com/article/2219018-overviewCastleman Disease: Practice Essentials, Pathophysiology, Etiology