Histopathological analysis of tumour types after intraperitoneal injection of mineral fibers in rats

Female rats were treated twice by an intraperitoneal injection of mineral fibres. The treatment led to malignant tumours in the peritoneal cavity. Most of these tumours were classified as malignant mesotheliomas. Some rats had undifferentiated sarcomas rather than mesotheliomas. Three different types of malignant mesotheliomas can be distinguished: epithelioid, sarcomatoid and mixed. Cartilaginous or osseous differentiation occuring in mesotheliomas has only been described as a biological feature in a few cases of mesotheliomas of the pleura in man (Goldstein, 1979; McCaughey, 1958; Yousem and Hochholzer, 1987). Some of the affected persons were known to have been exposed to asbestos (Goldstein, 1979; Yousem and Hochholzer, 1987). In the following report histopathological features of malignant mesotheliomas occurring in the abdominal cavity after intraperitoneal injection of different types of mineral fibres in female Wistar rats are described. Additionally, the number of animals with mesotheliomas, according to the injected fibre type is presented.