[Mesothelial cell. Cytology. Cytochemistry. Immunocytochemistry. Contribution of immunolabelling to the cytodiagnosis of serous effusions with cells of mesothelial aspect].

This paper reviews the contribution of cytochemical and immunocytochemical methods to the cytodiagnosis of serous fluids. For this purpose, 1000 fluids were reviewed (500 pleural and 500 peritoneal samples). The most reliable histochemical technique is the iron stain which labels macrophages. A minimum immunolabelling panel (including one or two epithelial markers and vimentin), applied to the identification of the usual phenotypes of reactive fluids with mesothelial cells or with macrophages, to adenocarcinomatous fluids and to malignant mesothelioma fluids, is proposed. The sensitivity and specificity of the reaction is discussed but, altogether the value of the method appeared rather limited as a correct diagnosis was obtained in 95% of cases by a careful morphological study.