Cells exfoliated from primary pleural mesotheliomas differ significantly from those from primary peritoneal tumors. In a quantitative study, it was shown that the pleural cells have larger nuclei, a more pronounced anisokaryosis and a higher nuclear-cytoplasmic ratio and, therefore, appear more malignant than the peritoneal cells, which have abundant cytoplasma and small nuclei. The differences in quantitative parameters were due to a more extensive vacuolization and consequent cytoplasmic distension, combined with nuclear compression in the case of peritoneal mesotheliomas. The morphometric parameters and the vacuolization patterns of cell populations in cases with both pleural and peritoneal involvement correlated with the data of the primary tumor regardless of the fluid in which the cells were found. This finding indicates the transcoelomic metastatic properties of malignant mesothelioma.

Ascitic Fluid↗

PubMedDate not supplied

Quantitative and qualitative differences between benign and malignant mesothelial cells in pleural fluid.

Quantitative as well as qualitative cellular parameters were investigated in 20 cases of reactive mesothelial proliferations and 40 cases of primary pleural mesotheliomas. The two groups showed statistically significant differences in the nuclear areas, cytoplasmic areas and standard deviations. In the mesotheliomas, the mean nuclear area and the mean cytoplasmic area were larger than in the reactive proliferations. Nine cases could not be properly classified with these quantitative parameters alone. Qualitative analysis revealed highly characteristic features in the mesotheliomas. Morula formation as well as irregular and coarse reticular chromatin patterns were strongly indicative of mesothelioma. The location and shape of the nucleus and the type and amount of cytoplasmic vacuolization gave additional information for distinguishing between the two groups.

Diagnosis, Differential↗