MUC1 and pleural mesothelioma: We evaluated the diagnostic performance of two immunocytochemical dual stains BerEp4/Calretinin and Desmin/Epithelial Membrane Antigen (EMA) on 149 ethanol‐fixed cytospin preparation as an initial step to differentiate pleural mesothelioma from metastatic adenocarcinoma and reactive mesothelial proliferations.