Malignant lymphoma in pleural effusions: An immunocytochemical cell surface analysis

Abstract

Nine malignant pleural effusions due to lymphoma were immunocytochemically analyzed with the peroxidase‐antiperoxidase adhesive slide assay for detection of cell surface antigens using a broad panel of monoclonal antibodies. The study population included one case of hairy‐cell leukemia; four cases of B cell non‐Hodgkin's lymphoma (B‐NHL), low malignant grade; two cases of B‐NHL, high malignant grade; one case of Hodgkin's disease; and one case of plasmacytoma. In the cases of B cell lymphoma, high percentages of B cells with monoclonal staining for kappa were found. In hairy‐cell leukemia, the hairy cells reacted with the monoclonal antibodies CD20, CD25, HLA‐DR, CD45, and HLA‐1. In Hodgkin's disease, the Hodgkin cells reacted with CD15, CD20, CD25, CD30, Tü9, and OKT9. The plasmacytoma case showed tumor cells negative for CD20, HLA‐DR, and CD45; partially positive for CD38; positive for HLA‐1; rnonoclonally positive for lambda; and negative for heavy‐chain immunoglobulins. The analysis of nonmalignant lymphocyte subpopulations revealed CD4/CD8 ratios similar to those in effusions of other etiologies. The percentages of natural killer cells (Leu‐7‐positive and CD16‐positive) were small and also similar to percentages in effusions of other etiologies. We conclude that immunocytochemical analysis of pleural effusions allows a clear recognition of B lymphoma cells and also of Hodgkin and hairy cells and that the distribution of nonmalignant lymphocyte subsets is indistinguishable from those found in other malignant and nonmalignant effusions.