Castleman

Castleman Disease

Castleman disease, also known as Castleman syndrome, is a rare disorder characterized by non-cancerous growths that may develop in the lymph node tissue throughout the body. It is named after Dr. Benjamin Castleman, who first described the condition in the 1950s. Castleman disease can occur in a unicentric form, affecting a single lymph node, or a multicentric form, affecting multiple lymph nodes and potentially leading to systemic symptoms.

Classification

Castleman disease is classified into two main types:

Unicentric Castleman Disease (UCD)

Unicentric Castleman disease involves a single lymph node or a single group of lymph nodes. It is the more common and less severe form of the disease. Patients with UCD often do not exhibit systemic symptoms, and the condition is usually discovered incidentally during imaging or surgery for another reason. Surgical removal of the affected lymph node is often curative.

Multicentric Castleman Disease (MCD)

Multicentric Castleman disease affects multiple lymph nodes and can lead to systemic symptoms such as fever, night sweats, weight loss, and fatigue. MCD is associated with more severe complications and can be life-threatening. It is often linked with human herpesvirus 8 (HHV-8) infection, especially in patients with HIV/AIDS. Treatment for MCD may include immunosuppressive therapy, antiviral drugs, and monoclonal antibodies such as siltuximab or rituximab.

Pathophysiology

The exact cause of Castleman disease is not well understood. However, it is believed to involve dysregulation of the immune system, leading to overproduction of cytokines, particularly interleukin-6 (IL-6). This cytokine storm can cause the lymph nodes to enlarge and may lead to systemic symptoms in multicentric cases.

Diagnosis

Diagnosis of Castleman disease typically involves a combination of imaging studies, laboratory tests, and histopathological examination of the lymph node tissue. Imaging studies such as CT or MRI scans can help identify enlarged lymph nodes. A biopsy of the affected lymph node is necessary to confirm the diagnosis and to differentiate Castleman disease from other lymphoproliferative disorders.

Treatment

The treatment of Castleman disease depends on the type and severity of the condition:

• Unicentric Castleman Disease:Surgical excision of the affected lymph node is the primary treatment and is often curative.
• Multicentric Castleman Disease:Treatment may include medications to reduce the immune response, such as corticosteroids, immunosuppressants, and monoclonal antibodies targeting IL-6 or CD20. Antiviral therapy may be used in cases associated with HHV-8.

Prognosis

The prognosis for unicentric Castleman disease is generally excellent following surgical removal of the affected lymph node. The prognosis for multicentric Castleman disease varies depending on the underlying cause, the patient's overall health, and the response to treatment. Early diagnosis and appropriate management are crucial for improving outcomes.

Also see

• Lymphadenopathy
• Lymphoproliferative disorder
• Human herpesvirus 8
• Interleukin-6