Minimally invasive diagnosis of acquired immunodeficiency syndrome-related primary central nervous system lymphoma.

The detection of Epstein-Barr virus (EBV)-DNA in cerebrospinal fluid (CSF) by means of the polymerase chain reaction (PCR) has been revealed, in retrospective studies, to be a good marker of primary central nervous system lymphoma (PCNSL) related to acquired immunodeficiency syndrome (AIDS); however, the technique's usefulness in the management of AIDS patients with focal brain lesions is still unknown. We studied the clinical usefulness of testing CSF obtained by lumbar puncture for the presence of EBV-DNA as a minimally invasive approach to the diagnosis of AIDS-PCNSL in patients with focal brain lesions. Human immunodeficiency virus (HIV)-infected patients with focal brain lesions, observed prospectively during a 30-month period, underwent lumbar puncture if not contraindicated; otherwise, ventricular CSF was obtained at brain biopsy. The presence of EBV-DNA was determined by means of PCR. We evaluated 122 patients: 42 diagnosed with brain lymphoma and the remaining 80 diagnosed with other brain disorders. Cerebrospinal fluid was collected from 101 patients--by lumbar puncture in 95, including 40 patients with AIDS-PCNSL. The sensitivity and specificity of PCR for EBV-DNA detection in lumbar CSF were 80% (95% confidence interval [CI] = 60.9%-91.6%) and 100% (95% CI = 92.6%-100%), respectively. Lumbar puncture and subsequent assessment of EBV-DNA would have allowed a correct diagnosis in 63.2% (95% CI = 46.0%-77.7%) of patients with AIDS-PCNSL and excluded this diagnosis in 76.3% (95% CI = 65.2%-84.8%) of patients without lymphoma (because EBV-DNA was not detected). The presence of EBV-DNA in lumbar CSF is a sensitive and highly specific diagnostic marker of AIDS-PCNSL, and EBV-DNA detection in this fluid may allow a minimally invasive diagnosis in a large percentage of patients with brain lymphomas.