[Findings on the pathology of mesotheliomas and their morphological diagnosis]

The data arising out of an extensive series of necropsies and operations on cases of mesothelioma observed between 1960 and 1974 in Genoa, a town where the incidence of this type of cancer is high, are reported. Macro- and microscopic and traditional histochemical diagnostic criteria are discussed and judgest to be largely insecure for a diagnosis of mesothelioma. In doubtful cases only the use of the electronic microscope is considered valid for diagnostic purposes. Particular attention is paid to the finding of endocytoplasmatic microfilaments of actomyosin type in mesotheliomatous cells and of microvill on free surfaces and at cell interfaces. For comparative purposes, ultrastructural findings in tumours which often involve pleural metastasis and are able to simulate a mesothelioma, are reported.