Evaluation of a cell block method in cytological diagnostics

Cell block procedures have now become an established part of cytological diagnostics. In this study a cytoblock technique based on the plasma-thrombin method was evaluated. In total 389 consecutive cytological samples were initially analyzed by the classical procedure and then by the cell block technique. The latter was done by centrifugation of the remaining material of the cytological sample, resuspension of the cells in blood plasma followed by generation of a cell clot by the addition of thrombin. Analysis of material from the peritoneal cavity, ascites and pleura was successful in more than 90% of cases. In 272 samples the conventional and cell block analyses revealed concordant results according to Papanicolaou classification. In 23 cases the cell block analysis induced an upgrade. In particular, malignant processes (PAP V) or precursor lesions (PAP IV) were identified in 9 cases which were not diagnosed by conventional analysis. Advantages of this method include the assessment of an additional sample volume and thus reduction of sampling error, the possibility for unlimited storage and molecular testing similar to histological samples.