Malignant pleural effusion in Hodgkin's lymphoma. Report of a case with immunoperoxidase studies.

The cytologic and histopathologic findings in a patient with Hodgkin's lymphoma, mixed cellularity type, and a malignant pleural effusion are presented. The consistency of staining with a battery of immunoperoxidase monoclonal antibody stains, including leukocyte common antigen, Leu-M1, UCHL1 and L26, was examined on sections of formalin-fixed lymph nodes and alcohol-fixed pleural fluid cell blocks. In addition, these same tissues were stained with carcinoembryonic antigen, B72.3, cytokeratin and epithelial membrane antigen immunoperoxidase antibodies to differentiate the tumor cells from reactive mesothelial cells and adenocarcinoma cells. The results on the pleural fluid specimens were consistent with what is known of the immunohistochemical staining properties of Hodgkin's lymphoma cells in lymph nodes.