Castleman disease

Castleman disease (CD) describes a group of rare lymphoproliferative disorders that involve enlarged lymph nodes, and a broad range of inflammatory symptoms and laboratory abnormalities. Whether Castleman disease should be considered an autoimmune disease, cancer, or infectious disease is currently unknown. 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 in a portion of cases. Correctly classifying the Castleman disease subtype is important, as the three subtypes vary significantly in symptoms, clinical findings, disease mechanism, treatment approach, and prognosis. All forms involve overproduction of cytokines and other inflammatory proteins by the body's immune system as well as characteristic abnormal lymph node features that can be observed under the microscope. In the United States, approximately 4,300 to 5,200 new cases are diagnosed each year. Castleman disease is named after Benjamin Castleman, who first described the disease in 1954. The Castleman Disease Collaborative Network is the largest organization dedicated to accelerating research and treatment for Castleman disease as well as improving patient care.