T and B lymphocyte markers in effusions of patients with non-Hodgkin's lymphoma.

T and B cells were sought in effusion fluids of 13 patients with lymphoma. In T cell lymphomas (four cases) morphologically abnormal cells that formed E rosettes were present. In B cell lymphomas (nine cases) morphologically abnormal cells were present in only two cases, however immunological studies showed a reduction in T cells and monoclonal light chain immunoglobulin expression in six of nine cases.