MODM are associated with a poorer survival compared to patients with SODM. A serum Tg level >30 ng/mL at the time of first distant metastases confers more than a fivefold risk of having MODM identified during follow-up.

Synchronous malignant mesothelioma with carcinomas in asbestos-exposed workers is rare and identified in 1.8% of 500 malignant mesotheliomas in this series. In most cases the carcinoma represents a primary bronchogenic neoplasm. Primary lung carcinomas are recognized to be asbestos related only when occurring in association with asbestosis. In this series this combination (bronchogenic carcinoma and asbestosis) was seen in four (0.8%) cases. In post-mortem cases for possible malignant mesothelioma it is important to identify any other neoplasia and determine whether it is related to asbestos. Their presence impact upon anticipated life expectancy and in the presence of malignant mesothelioma will affect the compensation settlement.

For staging purposes the designation of a tumour as invading perinephric tissues should be limited to those cases that have tumour cells invading the perinephric fat.