The pathologist's view of silicosis in 1930 and in 2015. The Johannesburg Conference legacy.

The 1930 International Labour Office Conference on silicosis in Johannesburg was a turning point in the history of silicosis and in the recognition of the associated pathologic patterns. Since 1930, pneumoconioses such as silicosis have become much rarer in developed countries and can now be diagnosed at an early stage based on clinical and radiologic criteria. However, in spite of these advances, pathologists must remember to look for silica in tissues, particularly when clinical and radiologic findings are more uncertain. Furthermore, nowadays pathologists essentially observe silicotic lesions as incidental findings adjacent to lung cancers. In addition to identifying the characteristic lesions, pathologists must also try to identify their causative agent, in the case of crystalline silica firstly by using polarized light examination, followed as appropriate by more sophisticated devices. Finally, pathologists and clinicians must always keep in mind the various implications of exposure to silica compounds in a wide range of diseases.