Pleural fluid cytology of Hodgkin's disease: cytomorphologic features and the value of immunohistochemical studies

Two cases in which Hodgkin's disease (HD) was cytologically diagnosed in pl eural effusions are presented. The presence of Reed-Sternberg (R-S) cells w as confirmed by positive staining for both CD15 and CD30, and negative stai ning for leukocyte common antigen. In addition, the differential diagnosis of HD in effusion cytology is presented, including look-alikes of R-S cells that can potentially lead to an incorrect diagnosis. To the best of our kn owledge, we believe this is only the second cytologic report of HD diagnose d in a pleural effusion using immunohistochemistry! to confirm the diagnosi s. Diagn. Cytopathol. 2000,22:21-24. (C) 2000 Wiley-Liss, Inc.