Higher positive identification of malignant CSF cells using the cytocentrifuge than the Suta chamber

Abstract

The most useful laboratory test for diagnosing neoplastic meningitis infiltration is cerebrospinal fluid (CSF) investigation. Accurate diagnosis is important for diagnostic, therapeutic, and prognostic consequences 1 . Cerebrospinal fluid cytology is mandatory in all cases of known or strongly suspected malignancy. This is particularly true in cases of leukemia and lymphoma, in which the results of CSF cell counts and cytology are important factors in determining and monitoring treatment 2,3,4 .The two main methods of CSF cell concentration are cytocentrifugation and the gravitational facility sedimentation chamber. The literature provides no consensus on the optimal technique 5,6 , since both methods have advantages and disadvantages. The aim of this paper was to compare two different methods of cell concentration, cytosedimentation using a Suta chamber and cytocentrifugation. ABSTRACTObjective: To define how to best handle cerebrospinal fluid (CSF) specimens to obtain the highest positivity rate for the diagnosis of malignancy, comparing two different methods of cell concentration, sedimentation and cytocentrifugation. Methods: A retrospective analysis of 411 CSF reports. Results: This is a descriptive comparative study. The positive identification of malignant CSF cells was higher using the centrifuge than that using the Suta chamber (27.8% vs. 19.0%, respectively; p = 0.038). Centrifuge positively identified higher numbers of malignant cells in samples with a normal concentration of white blood cells (WBCs) (< 5 cells/mm 3 ) and with more than 200 cells/mm 3 , although this was not statistically significant. There was no lymphocyte loss using either method. Conclusions:Cytocentrifugation positively identified a greater number of malignant cells in the CSF than cytosedimentation with the Suta chamber. However, there was no difference between the methods when the WBC counts were within the normal range.Keywords: cerebrospinal fluid; cytology, centrifugation, sedimentation. RESUMOObjetivo: Definir qual a melhor forma de concentrar amostras de LCR para obter maior porcentagem de positividade para o diagnóstico de infiltração neoplásica. comparando dois métodos diferentes de concentração de células, sedimentação e citocentrifugação. Métodos:Análise retrospectiva de 411 laudos de LCR. Resultados: Estudo comparativo descritivo. A identificação de células neoplásicas no LCR foi mais elevada quando usada a citocentrífuga do que a câmara de Suta (28% vs 19,0%, respectivamente; p = 0,038). Centrifugação identificou maior número de células neoplásicas em amostras com concentração de células < 5 células/mm 3 e superior a 200 células/mm 3 , embora não significativo. Não houve perda de linfócitos usando qualquer um dos métodos. Conclusões: A citocentrifugação identificou um número maior de células malignas no LCR do que a sedimentação com a câmara de Suta. No entanto, não houve diferença entre os métodos quando as contagens de leucócitos estavam dentro do intervalo normal.Palavras-chave: líquido cefalorraquidiano; citolog...