A sixty-one-year-old man who was a current smoker visited Toyama University Hospital for the investigation of abnormal chest shadowing. Restrictive ventilatory impairment and diffusion disturbance were found on pulmonary function testing．On high-resolution chest computed tomography (chest HRCT), paraseptal emphysema was found in the upper lung fields, as well as paraseptal emphysema and coexisting fibrotic change and ground-glass opacification in the middle lobe lingula and immediately below the pleura of the lower lobe. These findings suggested combined pulmonary fibrosis and emphysema (CPFE).
Thoracoscopic lung biopsy was performed for diagnosis. The pathological findings revealed that the alveoli were filled with macrophages, and lymphocytic infiltration and fibrotic changes were detected in the alveolar septa. These findings are typical of desquamative interstitial pneumonia (DIP). Lung function and laboratory data improved only on cessation of smoking. DIP is a smoking-related interstitial lung disease which might be considered to be CPFE on the basis of chest HRCT findings.