Idiopathic multicentric Castleman disease

Idiopathic Multicentric Castleman Disease (iMCD) is a rare and serious lymphoproliferative disorder characterized by the non-cancerous growth of lymph nodes with systemic symptoms. iMCD is one of the subtypes of Castleman Disease, which also includes Unicentric Castleman Disease (UCD) and Human Herpesvirus 8 (HHV-8)-associated multicentric Castleman disease. Unlike UCD, which affects a single lymph node region, iMCD involves multiple regions and is not associated with HHV-8. The cause of iMCD remains unknown, hence the term "idiopathic."

Symptoms

iMCD patients may experience a wide range of symptoms, including fever, fatigue, night sweats, unexplained weight loss, and an enlarged liver or spleen (hepatosplenomegaly). Laboratory findings often show anemia, elevated inflammatory markers, and hypergammaglobulinemia. The symptoms can mimic those of lymphoma, making the diagnosis challenging.

Diagnosis

The diagnosis of iMCD is based on a combination of clinical, laboratory, and histopathological findings. A key diagnostic criterion is the presence of characteristic histopathological features in the lymph node biopsy, showing multicentric lymphadenopathy with specific changes, such as regressed germinal centers and increased vascularity. Imaging studies, such as CT scans or MRI, are used to assess the extent of lymph node involvement and organomegaly.

Treatment

Treatment for iMCD aims to control symptoms and prevent organ damage. Therapies may include corticosteroids, immunosuppressive drugs, and biological agents targeting specific pathways involved in the disease. The anti-IL-6 receptor antibody, tocilizumab, has shown efficacy in treating iMCD and is approved for use in some countries. In severe cases, chemotherapy may be considered.

Prognosis

The prognosis of iMCD varies. Some patients respond well to treatment and can achieve long-term remission, while others may experience relapses or progress to more severe conditions, such as organ failure or lymphoma. Early diagnosis and appropriate treatment are crucial for improving outcomes.

Epidemiology

iMCD is a rare disease, with the exact incidence and prevalence unknown. It can affect individuals of any age but is more commonly diagnosed in adults.

Research

Research on iMCD is ongoing, focusing on understanding its pathogenesis, improving diagnostic criteria, and developing more effective treatments. The discovery of IL-6's role in the disease has been a significant advancement, leading to targeted therapies that have improved patient outcomes.