BACKGROUND: Castleman's disease is an uncommon disease and the histopathogenesis is poorly understood. This study aims to investigate their clinicopathological and immunophenotypic profile. MATERIALS AND METHODS: Castleman's disease was reconfirmed in biopsy tissue from 10 patients in a period of 17 years. Immunohistochemical staining was performed on the archival materials, with antibodies to lymphoid antigens and oncogene products, Bcl-6 and Bcl-2. Six reactive hyperplastic lymph nodes and three tonsils were used for comparative study of the phenotypic expression. RESULT: There were three cases of plasma-cell and seven of hyaline-vascular variant. The ages of patients ranged from eight to 60 years (median 30 years). The three patients with plasma-cell variant were older, all females. Two of the plasma-cell variant had multicentric lesions associated with systemic disease. All patients with hyaline-vascular variant had localised disease. Atrophic follicle centres were present in all the diagnostic tissue of both subtypes, with loss of Bcl-6 follicular centre B-cells and presence of relatively few CD57 T-cells. These follicle centres stained strongly with anti-CD21. In the mantle zone, CD5 expression was observed in only two cases and Bcl-2 expression similar to reactive follicles was present in six. CONCLUSION: Loss of Bcl-6 B-cells in the atrophic follicle centres, characteristic CD21 network patterns, low rate of CD5 and Bcl-2 expression in the mantle-zone lymphocytes are present in both variants of Castleman's disease, differ distinctly from reactive follicles. The phenotypic similarity in these two variants suggests possibility of closely related pathogeneses.
BACKGROUND:Castleman's disease is an uncommon disease and the histopathogenesis is poorly understood. This study aims to investigate their clinicopathological and immunophenotypic profile. MATERIALS AND METHODS:Castleman's disease was reconfirmed in biopsy tissue from 10 patients in a period of 17 years. Immunohistochemical staining was performed on the archival materials, with antibodies to lymphoid antigens and oncogene products, Bcl-6 and Bcl-2. Six reactive hyperplastic lymph nodes and three tonsils were used for comparative study of the phenotypic expression. RESULT: There were three cases of plasma-cell and seven of hyaline-vascular variant. The ages of patients ranged from eight to 60 years (median 30 years). The three patients with plasma-cell variant were older, all females. Two of the plasma-cell variant had multicentric lesions associated with systemic disease. All patients with hyaline-vascular variant had localised disease. Atrophic follicle centres were present in all the diagnostic tissue of both subtypes, with loss of Bcl-6 follicular centre B-cells and presence of relatively few CD57 T-cells. These follicle centres stained strongly with anti-CD21. In the mantle zone, CD5 expression was observed in only two cases and Bcl-2 expression similar to reactive follicles was present in six. CONCLUSION: Loss of Bcl-6 B-cells in the atrophic follicle centres, characteristic CD21 network patterns, low rate of CD5 and Bcl-2 expression in the mantle-zone lymphocytes are present in both variants of Castleman's disease, differ distinctly from reactive follicles. The phenotypic similarity in these two variants suggests possibility of closely related pathogeneses.