Ninety-eight percent of the cells isolated from a malignant pleural effusion in a case of American Burkitt's lymphoma showed membrane fluorescence to antihuman IgM antisera, while only 2% of the cells formed spontaneous rosettes with sheep red blood cells. It is concluded that the Burkitt cells in the malignant effusion are derived from bursal equivalent lymphocytes. Epstein-Barr (E-B) viral titers to both viral capsule antigen and early antigen were not elevated. The significance of these findings is discussed.

A prospective evaluation of the nitroblue tetrazolium (NBT) dye reduction reaction revealed that the response of neutrophils from 76 lymphoma patients was comparable to a control population of 44 patients without underlying malignancy. The NBT test proved to be a useful adjunct in distinguishing fever as a systemic manifestation of underlying lymphoma from that secondary to bacterial infection. In contrast to lymphoma patients with „B”︁ fever, bacterially‐infected lymphoma patients had elevated resting NBT scores comparable to a control population with bacterial infections. Lymphoma chemotherapy, including prednisone, did not inhibit neutrophilic response to infection or latex particle phagocytosis, but Procarbazine may have produced a false positive response in some patients. It is essential to perform a simultaneous latex particle stimulation control to rule out an acquired intracellular defect that would otherwise be interpreted as a false negative response.