Benign asbestos pleural diseases.

The global incidence of asbestos-related lung diseases is expected to continue to rise. Although much attention is devoted to malignant diseases induced by asbestos, benign asbestos pleural diseases (pleural plaques, benign asbestos-related pleural effusion, diffuse pleural thickening, and rounded atelectasis) are common in clinical practice and often produce diagnostic difficulties. The authors describe the clinical features of benign asbestos-related pleural disease, before focusing on recent advances in radiology and on controversies surrounding the pathogenesis of asbestos-induced pleural injury. Advances in computed tomography have assisted the understanding and diagnosis of these diseases, and increasing evidence suggests radiologic appearances on computed tomography can predict impairment in pulmonary function tests. The pathogenesis of asbestos-induced pleural diseases has also been subject to extensive investigation. Asbestos fibers can provoke pleural inflammation from direct toxicity to mesothelial cells. Inhaled asbestos fibers can also elicit pleural injury indirectly via the release of growth factors and inflammatory cytokines from within the lung. Although progress has been made in the understanding of the mechanisms of asbestos pleural injury, many important questions remain unanswered. The role of genetic factors and possible environmental cofactors (eg, simian virus 40) in the pathogenesis of benign asbestos pleural diseases requires further research.