Background: In Germany, asbestos-related diseases (asbestosis, lung cancer, mesothelioma) are recognised and compensated occupational diseases. The histologic diagnosis of mesothelioma is sometimes a challenge; additional immunohistochemical and molecular methods are needed. With lung dust analysis, the current asbestos fibre burden of the lung is measured (biomonitoring). Identification of grade I asbestosis (minimal asbestosis) requires directed histological examinations with up to 400-fold magnification, additional iron staining and possibly in connection with a lung dust analysis.
Objectives: Demonstration of current pathologic diagnostics in association with mesothelioma and lung dust analysis.
Materials and methods: Analysis of routine data from the German Mesothelioma Register.
Results: Contrary to reactive mesothelial hyperplasia, malignant mesotheliomas have a nuclear BAP1 loss-of-expression in up to 66% of cases. For differential diagnosis between reactive versus malignant, a p16-FISH test may be helpful. BAP1 loss-of-expression and p16-deletion are independent markers. Evaluation of the dataset of the German Mesothelioma Register of patients with repeated tissue sampling proves the detection of asbestos fibres at the same level even after 40 years. The asbestos fibre burden in the human lung remains stable over this long period of time. In the electron microscopic analysis, white asbestos was predominantly found.
Conclusions: The well-known and industrially appreciated characteristics of asbestos fibres (in ancient ἄσβεστος asbestos "imperishable") as biopersistent have also been experimentally confirmed in human lungs.
Keywords: Asbestos; BAP1; Lung; Pleura; p16-Deletion.