Exposure to smoke is associated with the development of diseases of the airways and lung parenchyma. Apart from chronic obstructive pulmonary disease (COPD) and lung cancer, in some individuals, tobacco smoke can also trigger mechanisms of interstitial damage that result in various pathological changes and pulmonary fibrosis. A causal relation has been established between tobacco smoke and respiratory bronchiolitis‑associated interstitial lung disease (RB‑ILD), pulmonary Langerhans cell histiocytosis (LCH), desquamative interstitial pneumonitis (DIP), acute eosinophilic pneumonia (AEP), and interstitial fibrosing lung diseases.
The evidence of combined lower lung fibrosis and predominant upper lung emphysema is renowned as a distinct clinical entity, named combined pulmonary fibrosis and emphysema. Localized or nonspecific fibrosis accompanied by emphysematous changes is also a frequent pathological finding in smokers and is known as airspace enlargement with fibrosis or smoking‑related interstitial fibrosis. Although computed tomography (CT) permits an adequate classification and distinction of these diseases, the clinical, imaging, and histological features often overlap and coexist in a single patient because of the likely interconnection between the mechanisms involved in inflammation and pulmonary fibrosis.
This presentation aims to describe the high‑resolution CT (HRCT) findings in this group of disease entities in correlation with the clinical manifestations and histological changes underlying the radiological pattern.
Competing Interest
The author has no competing interests to declare.