Diagnostic differentiation between reactive and malignant lymphoid cells in serous effusions.

Lymphoid cell components in a total of 34 pleural and ascitic aspirates were investigated immunologically. The results indicate that reactive lymphocytes predominate in effusions from non-haemopoietic malignancies and benign conditions, while a significant proportion of fluids from patients with non-Hodgkins lymphoma show unequivocal evidence of lymphomatous involvement. Immunological typing of lymphocytes in serous effusions is a valuable adjunct to conventional methods of diagnosis particularly in those patients in whom invasive procedures are undesirable.