Castleman’s Disease

Angiofollicular hyperplasia

Giant lymph node hyperplasia

Epidemiology and Etiology:

• Localized type:
• Much more frequent
• Multicentric type:
• Hyaline vascular type (>90%):
• Plasma cell type:
• Diagnosis of exclusion, when all other possible causes of follicular hyperplasia have been ruled out
• Note that Castleman-like changes can be seen in Hodgkin Disease

Common sites:

• Localized type:
• Solitary mediastinal mass
• Other sites:
• Axillary
• Cervical
• Skeletal muscles
• Pulmonary parenchyma
• Plasma cell type (~10%):
• Abdominal cavity
• Small bowel mesentery particularly
• Mediastinum
• Peripheral nodes
• Extranodal

Gross features:

•  .

Histologic features:

• hyaline vascular type:
• atrophic germinal centres (regressively transformed)
• expanded mantle zone with concentric rings of lymphocytes (“onion skin” pattern)
• multiple regressively transformed germinal centres within one “cloud” of mantle cells
• may completely obscure the germinal center
• hyaline blood vessels entering into follicles
• interfollicular vascularity increased
• few interfollicular lymphocytes or plasma cells
• increased numbers of follicular dendritic cells
• may appear large and bizarre
• plasma cell type:
• florid follicular hyperplasia
• well-defined mantle zone
• marked interfollicular plasmacytosis
• mature plasma cells
• scattered immunoblasts
• absent vascular proliferation or hyalinization usually
• absence of Hodgkin cells

Immunophenotype:

Marker:	Sensitivity:	Specificity:
IgL light chain (monotypic)	40% of plasma cell type

Molecular features:

•  .

Other features:

• plasma cell variant:
• polyclonal gamma globulinemia often
• IL-6 serum level increased often
• ESR elevated often
• Anemia frequently
• POEMS syndrome:
• Polyneuropathy
• Organomegaly
• Endocrinopathy
• Monoclonal protein
• Skin lesions

References:

•  Essentials of Anatomic Pathology, 2^nd Ed (2006)