Discovery of a New Subtype of Castleman Disease After 45 Years

In a groundbreaking development, researchers have identified a new subtype of Castleman disease (CD), marking the first such discovery in over four decades. This advancement is expected to significantly improve diagnosis and treatment options for countless patients who previously fell into classification gaps. The newly recognized condition, termed "Oligocentric Castleman Disease" (OligoCD), is a distinct clinical entity that differs markedly from the previously known types of CD.

Castleman disease, first described in 1956 by Dr. Benjamin Castleman, is a rare disorder characterized by abnormal lymph node growth and a spectrum of symptoms ranging from mild discomfort to severe, life-threatening complications. Traditionally, CD has been categorized into unicentric Castleman disease (UCD), involving a single lymph node region and generally less severe, and idiopathic multicentric Castleman disease (iMCD), which involves widespread lymphadenopathy and intense cytokine-driven inflammation. However, clinical observations highlighted that some patients did not fit neatly into these classifications, leading to diagnostic challenges.

Using the comprehensive ACCELERATE registry—integrating medical data from hundreds of CD patients—a team of clinicians and hematopathologists analyzed 179 cases. Their findings revealed that OligoCD manifests with fewer and less severe symptoms than iMCD. In many cases, affected lymph nodes could be effectively treated through surgical removal, which is often sufficient for UCD, as opposed to more aggressive therapies used for iMCD, such as IL-6 inhibitors, immunosuppressants, and chemotherapies.

This discovery is significant because it offers a clearer framework for diagnosing and managing CD. Patients previously misclassified or subjected to overly aggressive treatments can now be accurately identified and matched with more suitable interventions. The research team emphasizes the importance of further studies to understand how OligoCD develops and to refine treatment guidelines. The ongoing efforts facilitated by the ACCELERATE registry are expected to continue shedding light on the heterogeneity of this rare disease.

Dr. David Fajgenbaum, a key researcher and co-founder of the Castleman Disease Collaborative Network (CDCN), expressed optimism about these findings. "This discovery is a game-changer for Castleman disease patients," he stated. "For decades, individuals with OligoCD have been treated based on assumptions that did not reflect their specific condition, often leading to unnecessary side effects. Now, we can tailor treatments more precisely."

Patient stories, including that of Penny Deremer—a CDCN member and Penn Medicine patient with OligoCD—highlight the real-world impact of this advancement. "I am so thankful to finally have a name for what I’ve been going through," she shared.

In summary, this discovery not only advances scientific understanding but also offers hope for improved patient outcomes through personalized medicine approaches. Ongoing research aims to further delineate OligoCD and enhance treatment protocols, ultimately benefitting thousands of patients living with this complex disorder.

Source: https://medicalxpress.com/news/2025-04-subtype-castleman-disease-years.html