Desquamative interstitial pneumonia with clinical, radiological and histologic correlation

Respiratory bronchiolitis-associated interstitial lung disease (ILD), desquamative interstitial pneumonia (DIP), and pulmonary Langerhans cell histiocytosis are entities of smoking-related ILD. While clinically regarded as 2 separate forms of idiopathic interstitial pneumonia, DIP, and respiratory bronchiolitis-associated ILD are thought to be representing ends of a continuous spectrum of disease that primarily affects tobacco smokers. This case report presents a 53-year-old female patient who has 58 pack-year smoking history who has been experiencing a dry cough and epigastric pains for 2 years. Open-lung biopsy is performed and histopathology indicated smoking-related interstitial fibrosis. The patient did not stop smoking, which after a year leads to significant clinical deterioration with a notable decrease in diffusion for carbon monoxide capacity. Upon smoking cessation and treatment with corticosteroids, a significant clinical improvement is achieved. In smokers complaining of cough and reduced exercise tolerance and in whom evidence of interstitial fibrosis is demonstrated radiologically, DIP should be considered as a differential diagnosis. Smoking is the exclusive etiologic factor of pathogenesis of DIP.