Diagnosis of CNS lymphoma using immunofluorescent phenotyping of CSF mononuclear cells

We describe the use of a panel of monoclonal antibodies, directed against leukocyte surface antigens to characterize CSF mononuclear cells with regard to malignancy when cytopathology was inconclusive. Cytocentrifuged preparations from three patients in which traditional modalities had not yielded a diagnosis were studied, utilizing a panel of antibodies for B and T cell antigens. All three patients were found to have B cell lymphoma of the CNS. Rapid institution of the appropriate therapy resulted in marked improvement of CNS symptoms in each case. Our results indicate that in patients with CNS disease and CSF pleocytosis of undefined nature, this technique may provide rapid and precise diagnostic information.