Angiofollicular lymph node hyperplasia

Angiofollicular Lymph Node Hyperplasia

Angiofollicular lymph node hyperplasia, also known as Castleman disease, is a rare lymphoproliferative disorder characterized by non-cancerous growths that may develop in the lymph node tissue throughout the body. It was first described by Dr. Benjamin Castleman in 1956. The disease can present in a unicentric form, affecting a single lymph node region, or a multicentric form, involving multiple lymph node regions and potentially leading to systemic symptoms.

Classification

Angiofollicular lymph node hyperplasia is classified into two main types:

• Unicentric Castleman Disease (UCD): This form involves a single lymph node or a single group of lymph nodes. It is often asymptomatic and may be discovered incidentally during imaging for other conditions. Surgical removal of the affected lymph node is usually curative.

• Multicentric Castleman Disease (MCD): This form involves multiple lymph node regions and can cause systemic symptoms such as fever, night sweats, weight loss, and fatigue. MCD is associated with more severe complications and may require systemic therapy.

Pathophysiology

The exact cause of angiofollicular lymph node hyperplasia is not well understood. However, it is believed to involve dysregulated immune responses and overproduction of cytokines, particularly interleukin-6 (IL-6). In some cases, MCD is associated with human herpesvirus 8 (HHV-8) infection, especially in individuals with HIV/AIDS.

Clinical Presentation

The clinical presentation of angiofollicular lymph node hyperplasia varies depending on whether the disease is unicentric or multicentric:

• Unicentric Castleman Disease: Patients may be asymptomatic or present with a palpable mass. Symptoms, if present, are usually due to compression of adjacent structures.

• Multicentric Castleman Disease: Patients often present with systemic symptoms such as fever, night sweats, weight loss, and fatigue. Lymphadenopathy is typically generalized, and hepatosplenomegaly may be present. Laboratory findings may include anemia, elevated inflammatory markers, and hypoalbuminemia.

Diagnosis

Diagnosis of angiofollicular lymph node hyperplasia is based on clinical evaluation, imaging studies, and histopathological examination of the lymph node tissue. A biopsy is essential to confirm the diagnosis and to differentiate it from other lymphoproliferative disorders.

Treatment

Treatment strategies differ between unicentric and multicentric forms:

• Unicentric Castleman Disease: Surgical excision of the affected lymph node is the treatment of choice and is often curative.

• Multicentric Castleman Disease: Treatment may include immunosuppressive therapy, monoclonal antibodies targeting IL-6 (such as siltuximab), antiviral therapy in HHV-8-associated cases, and chemotherapy in severe cases.

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 and depends on the underlying cause, the presence of associated conditions such as HIV, and the response to treatment.

Also see

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