The cytology of malignant mesothelioma in Western Australia.

The cytology of malignant mesothelioma seen in 12 patients associated with the mining of crocidolite asbestos in Western Australia is described. Two main patterns of mesothelioma were observed: the spindle cell and epithelial varieties. In the more common epithelial variety, five features were found to be of particular value in making a cytologic diagnosis. These include the finding of cell aggregates, multinucleation, the presence of brush-like borders, the close apposition of cell borders, and a characteristic cytoplasm. A diagnosis of malignant mesothelioma may be established by cytologic examination of effusions. The awareness of the possible occurrence of such a primary malignant neoplasm with the features outlined may be helpful in this regard.