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 pleural effusions are presented. The presence of Reed-Sternberg (R-S) cells was confirmed by positive staining for both CD15 and CD30, and negative staining 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 knowledge, we believe this is only the second cytologic report of HD diagnosed in a pleural effusion using immunohistochemistry to confirm the diagnosis. Copyright 2000 Wiley-Liss, Inc.