Abstract: | The nuclear DNA contents of atypical mesothelial cells from five patients who had an eosinophilic pleural effusion (EPE) were studied by the use of DAPI (4′,6-diamidino-2-phenylindole dihydrochloride) DNA staining. Analysis of the nuclear DNA content revealed a polyploid pattern, with a major peak in the tetraploid region. Using an immunocytochemical technique, the atypical mesothelial cells showed a positive reaction for cytokeratin. In contrast carcinoembryonic antigen (CEA) was always negative in these cells. It is suggested that the atypical mesothelial cells with EPE had a higher rate of proliferation than did the normal mesothelial cells. |