Hyaline-Vascular Castleman Disease : Immunophenotype

Comments:
Immunophenotype of Hyaline-Vascular Castleman Disease (HVCD): In both hyaline-vascular as well as plasma cell type of Castleman disease, the follicles have reactive immunophenotype. B cells and plasma cells are polyclonal and the T-cells don't show any aberrant immunophenotype.

The follicular dendritic cells (FDC) are positive for CD21 and CD23. A single FDC meshwork may have multiple germinal centers.

The concentric layers of the expanded mantle zone are composed of CD20-positive B-cells (as shown here) that may also express CD5 in one-third of cases. The interfollicular areas show scattered or small clusters of TdT-positive T-cells in 75% of cases. Plasmacytoid dendritic cells in the interfollicular region stain for CD123, CD68, and CD43. Stain for HHV-8 is negative in HVCD.