A COMPARISON OF POLYMERASE CHAIN-REACTION EXAMINATION OF CEREBROSPINAL-FLUID AND CONVENTIONAL CYTOLOGY IN THE DIAGNOSIS OF LYMPHOMATOUS MENINGITIS

BACKGROUND. Inherent limitations of conventional cytology often result in a failure to diagnose lymphomatous meningitis in cerebrospinal flu id (CSF) specimens from patients who actually have the disease. The de velopment of polymerase chain reaction (PCR) techniques for the diagno sis of lymphoma based on the detection of clonal rearrangements of the immunoglobulin or T-cell receptor genes offers an alternative, DNA-ba sed test for the diagnosis of lymphoma in the CSF. METHODS. In this re trospective study, 31 CSF specimens from 21 patients were examined by a PCR technique that can detect clonal immunoglobulin gene rearrangeme nts. Twenty-four of the specimens came from 14 patients who eventually had definitive histologic or cytologic diagnoses of B-cell lymphoma. The other seven patients had other neurologic diagnoses, including two patients with reactive lymphocytosis, three with glioblastoma, one wi th metastatic carcinoma, and one with multi-infarct dementia. The resu lts of the PCR examinations were compared with cytologic evaluation of the same CSF specimens. RESULTS. Five of seven specimens from patient s with central nervous system lymphoma that were suspicious for, but n ot diagnostic of, lymphoma by conventional cytology were positive by P CR. Of 13 specimens from patients with lymphoma that showed no cytolog ic evidence of malignancy, 5 were positive by PCR. Two of four specime ns for which conventional cytology showed definitive evidence of lymph oma were positive by PCR. Two specimens from patients with a reactive lymphocytosis showed a polyclonal pattern by PCR. Specimens from patie nts with other neurologic diseases were negative by PCR even when cyto logically malignant (glioblastoma) cells were present in the specimen. CONCLUSIONS. PCR examination of CSF is practical, complements convent ional cytology, and sometimes provides the correct diagnosis when conv entional cytology yields only ambiguous results. (C) 1996 American Can cer Society.