[Interstitial lung diseases (ILD) in smokers: spectrum in high resolution computed tomography (HRCT)]

Smoking is a known risk factor for the development of various interstitial lung diseases, e.g. respiratory bronchiolitis, respiratory bronchiolitis-associated interstitial lung disease, desquamative interstitial pneumonia, and pulmonary Langerhans cell histiocytosis. These disorders frequently present with overlapping clinical pathological features and in addition may coexist within the same patient. In the clinical routine the differential diagnosis may be challenging or even impossible; therefore, smoking-related lung diseases are considered as part of the same disease spectrum representing different degrees of lung parenchymal damage secondary to cigarette smoke exposure. The role of cigarette smoking in the development of pulmonary fibrosis is complex and subject to intense investigation. It encompasses a subset of patients with nonspecific interstitial pneumonia where cigarette smoking may have played a causative role as well as patients with combined pulmonary fibrosis and emphysema (CPFE) as a novel entity with clearly defined clinical radiological features.