Clinical Significance of Cytocentrifuge Preparation Analysis of Low-Cell-Count Cerebrospinal Fluid Specimens.

Introduction: The usefulness of performing a cytocentrifuge preparation (CCP) analysis on cerebrospinal fluid (CSF) containing less than 5 cells has never been studied. To determine if the CCP analysis has a clinical impact on central nervous system (CNS) management of patients with CSF samples containing less than five cells, we correlated the result of CCP to cytomorphology and flow cytometry.

Methods: From November 20^th 2005 to July 18^th 2007, CCP analysis were performed on 105 CSF consecutive samples containing less than 5 cells from patients with various cancers. For each of these samples, a research via computerized data was conducted to obtain cytomorphology and flow cytometry results. If results were positive or inconclusive, the clinical history and treatment were reviewed.

Results: All 105 samples had negative CCP results. Of the 105 samples, 74 (70,5%) had available cytomorphologies, with 5 (6,8%) being positive, confirming central nervous system infiltration. All 5 patients received treatment for their CNS involvement. The sensitivity of cytomorphology was 83,3%(5/6) and its specificity 100% (68/68).Of the 105 samples, 23 (21,9%) had available flow cytometries: 4 of the 23 (17,4%) cytometries were positive, 2 correlated by positive cytomorphology and treated. 2 had negative cytomorphology with one patient receiving treatment. The sensitivity of cytometry was 75% (3/4) and the specificity 94,7% (19/20).

Conclusion: We found no advantage to performing CCP analysis on CSF samples of less than 5 cells. However, this suggests that performing both cytomorphology and flow cytometry allows a better detection and management of CNS infiltration.