Combined pulmonary fibrosis and emphysema: a commonly missed diagnosis

Results of lung function tests suggested that the shortness of breath was likely due to a combination of restrictive and obstructive lung defects (the former plays a dominant role). High-resolution computedtomography images of the thoraxshowing (a) centrilobular and paraseptalemphysematous change at bilateralupper zones; (b) at carina level, there isemphysematous change with subpleuralreticulations on the left side; and (c) atbasal regions, there is septal thickening withreticulations and honeycomb formation.(d) Coronal and (e) sagittal views showingarchitectural distortion and mild tractionbronchiectasis at bilateral basal regions.The radiological diagnosis was combinedpulmonary fibrosis and emphysema Pulmonary function testing on 17 January 2020 revealed severely diminished diffusing capacity for carbon monoxide (DLCO) of 35% (predicted: 19.1 mL/mmHg/min, best: 6.6 mL/mmHg/min) and carbon monoxide diffusion coefficient of 41% (predicted: 4.29 mL/mHg/min/L, best: 1.74 mL/mHg/min/L). In general, patients with CPFE have preserved FEV1 and FVC, but the diffusion capacity of the lung for carbon monoxide is severely diminished.1 Typically, CPFE is more common in men, current or former smokers.2 Some classic features of CPFE include the following: * More rapid lung function decline than in patients with chronic obstructive pulmonary disease (COPD) or idiopathic pulmonary fibrosis (IPF) alone.