[Ultrastructure of asbestos-induced mesotheliomas]

Experimental mesotheliomas induced in albino rats by treatment with isometric crocidolite asbestos were studied by light and electron microscopy. The cellular structure of different types of neoplasms was examined. The ultrastructural investigation was carried out using both freshly-resected materials and those recovered from paraffin blocks. The characteristic features of nuclei and cytoplasm are described with special attention being given to cytoplasmic organelles. On the basis of morphological light and electron microscopic study the authors discuss the histogenesis of different types of mesotheliomas. An attempt is being made to establish the origin of fibromatous mesotheliomas and to improve the available classifications.