In this episode, we review the Arthritis & Rheumatology manuscript, "Diagnosis and Treatment of Castleman Disease," with Drs. Luke Chen and David Fajgenbaum. The discussion (which provides an essential, up-to-date overview of a rare but critical disease) highlights the clinical subtypes of Castleman Disease, its overlap with autoimmune and autoinflammatory syndromes, and current diagnostic and treatment strategies. Dr. Chen offers a hematologist's perspective on disease classification, pathology, and practical management tips, while Dr. Fajgenbaum shares insights from his personal experience as a patient and his work advancing research through the Castleman Disease Collaborative Network and Every Cure.