[Pathologic observation of 298 rat mesotheliomas induced by asbestos]

Two hundred and ninety eight rat mesotheliomas induced by chrysotile or crocidolite were studies. The results demonstrated that tumor masses were scattered extensively. The appearance of tumor was polymorphous. According to the microscopic features, the 298 cases of mesothelioma could be histologically classified into three types, i.e. epithelial type, fibrous type and mixed cell type. The malignant mesothelioma is characteristic of its polymorphism and the clear cancernation of mesothelial cells.