Combined cytomorphologic and immunophenotypic approach to evaluation of effusions for lymphomatous involvement.

Combining cytomorphology and immunophenotypic data in evaluation of effusions for lymphomatous involvement is reliable, non-invasive, and expeditious. In this study, 30 effusion specimens from 30 patients with clinically suspected or previously diagnosed non-Hodgkin's lymphoma (NHL) were evaluated cytomorphologically and by flow cytometric immunophenotyping with a large panel of monoclonal antibodies. Of 11 patients with a previous diagnosis of NHL, 50% had cytomorphologic and immunophenotypic evidence of lymphomatous involvement of effusion specimens; therefore, flow cytometric immunophenotyping is recommended in these cases since there may be substantial therapeutic impact. In addition, 69% of the effusions positive for lymphomatous involvement represented newly diagnosed NHL; in 36% of these cases, tissue biopsy was not necessary since they were either high-grade (lymphoblastic or small, non-cleaved cell type) or of the small lymphocytic lymphoma cell type.