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Chapters

0:00 Introduction
0:53 Symptoms of Castleman Disease
1:58 Causes of Castleman Disease
2:24 diagnosis of Castleman Disease
2:51 Treatment of Castleman Disease


Castleman disease is a group of uncommon lymphoproliferative disorders characterized by lymph node enlargement, which often manifests without any other obvious symptoms.

Castleman disease includes at least three distinct subtypes: unicentric Castleman disease (UCD), human herpesvirus 8 associated multicentric Castleman disease (HHV-8-associated MCD), and idiopathic multicentric Castleman disease (iMCD). These are differentiated by the number and location of affected lymph nodes and the presence of human herpesvirus 8, a known causative agent. Correctly classifying the Castleman disease subtype is important, as the three subtypes vary significantly in symptoms, clinical findings, disease mechanism, treatment approach, and prognosis. In the United States, approximately 6,500 to 7,700 new cases are diagnosed each year.[1]

Castleman disease is named after Benjamin Castleman, who first described the disease in 1956. The Castleman Disease Collaborative Network is the largest organization focused on the disease and is involved in research, awareness, and patient support.[2]
The subtypes of Castleman disease reflect the number of lymph node regions with enlarged lymph nodes and known causes of the disease.[3] In unicentric disease, one or more enlarged lymph nodes are present in a single region of lymph nodes. In multicentric disease, enlarged lymph nodes are present in multiple regions of lymph nodes. The only known cause of Castleman disease is uncontrolled infection with human herpesvirus 8, which has only been reported in cases of multicentric disease.[3] There are three established subtypes of Castleman disease.[4]
Unicentric Castleman disease
Main article: Unicentric Castleman disease

In unicentric Castleman disease (UCD) one or more enlarged lymph nodes are present in a single region of lymph nodes. The cause of UCD is unknown.[5] It is the most common subtype of Castleman disease and compared to HHV-8-associated MCD and iMCD, symptoms are typically milder and relate to the lymph node affected, and organ dysfunction is uncommon. Surgical removal of enlarged lymph nodes is the treatment of choice, but in cases that resection is not an option, treatment is similar to iMCD cases.[6][7]
Idiopathic multicentric Castleman disease
Main article: Idiopathic multicentric Castleman disease

In idiopathic multicentric Castleman disease (iMCD), enlarged lymph nodes are present in multiple lymph node regions and no known cause for the disease is identified. It is less common than unicentric Castleman disease (UCD) and compared to UCD, symptoms are typically more severe, laboratory abnormalities must be present for diagnosis, and medications are used for treatment as surgery is ineffective.[6] Symptoms include systemic inflammatory and organ dysfunction. Medications used for treatment include antivirals, cytotoxic chemotherapy and rituximab.[1] Two great challenges in the diagnosis and treatment of iMCD are the spectrum of nonspecific symptoms and the unclear etiology of the disease.[8]
Human herpesvirus 8 associated multicentric Castleman disease
Main article: HHV-8-associated MCD

In human herpesvirus 8 associated multicentric Castelman disease (HHV-8-associated MCD), enlarged lymph nodes are present in multiple lymph node regions and infection with human herpesvirus 8 is present. It is less common than unicentric Castleman disease and diagnosed most frequently in patients infected with human immunodeficiency virus (HIV). Compared to UCD and iMCD, HHV-8-associated MCD presents with similar symptoms and clinical findings to iMCD. While UCD is readily treatable with surgery, HHV-8-associated MCD, like iMCD, is treated with medications as surgery is ineffective.[6]