Cytology of cerebrospinal fluid : Are polylysine-coated slides useful ?

OBJECTIVE: To determine the effect of the use of polylysine-coated (PLC) slides for cytocentrifugation on the morphology and number of cells in cerebrospinal fluid (CSF) and its effectiveness in improving the diagnostic sensitivity of the cytologic examination of CSF. STUDY DESIGN: We assessed the morphology and numbers of cells in 50 CSF samples obtained from 50 consecutive lumbar punctures. After centrifugation of the aliquots, 400 μL was used for cytocentrifugation on PLC and plain glass slides. After Giemsa staining, random area cell counts were made for a total of 100 microscopic fields (using a 40 x objective), and cytomorphology was assessed. RESULTS: There was no difference in cytomorphologic quality between PLC and plain glass slides. The total number of cells was higher on the PLC slides (30,674 vs. 28,426; mean value per slide, 614 vs. 569), with ranges of 0-11,076 (median value, 38) and 0-10,980 (median value, 24), respectively. This difference was significant (Wilcoxon matched-pairs signed-rank test, P<.05). The higher number of cells influenced the diagnostic assessment in one case, in which only the PLC slide was conclusive. CONCLUSION: A significantly higher number of cells was found when PLC slides were used in cytopathologic assessment of CSF samples, resulting, however, in only minor improvements in diagnostic sensitivity. These findings do not warrant the routine use of PLC slides during cytocentrifugation of CSF.