Combined Pulmonary Fibrosis and Emphysema: Comparative Evidence on a Complex Condition

Abstract

Combined pulmonary fibrosis and emphysema (CPFE) is a clinical syndrome characterized by upper lobe emphysema and lower lobe fibrosis manifested by exercise hypoxemia, normal lung volumes, and severe reduction of diffusion capacity of carbon monoxide. It has varying prevalence worldwide with a male predominance, and with smoking history of more than 40 pack-years being a common risk factor. The unique imaging features of CPFE emphasize its distinct entity, aiding in the timely detection of pulmonary hypertension and lung cancer, both of which are common complications. High-resolution computed tomography (HRCT) is an important diagnostic and prognostic tool, while lung cancer is an independent factor that alters the prognosis in CPFE patients. Treatment options for CPFE are limited, but smoking cessation, usual treatments of pulmonary fibrosis and emphysema, and avoidance of environmental exposures are encouraged.

Keywords: emphysema; interstitial lung disease; lung fibrosis; lung function; pulmonary hypertension.

Figure 1

Factors associated with Combined Pulmonary Fibrosis and Emphysema. Abbreviations: IPF—idiopathic pulmonary fibrosis, CTD-ILD—connective tissue disease-associated interstitial lung disease, RA-ILD—rheumatoid arthritis-associated interstitial lung disease, SS-ILD—systemic sclerosis-associated interstitial lung disease, c-ANCA—antineutrophil cytoplasmic autoantibody, fHP—fibrotic hypersensitivity pneumonitis.

Figure 2

HRCT patterns in CPFE. A predominant pattern of centrilobular emphysema in the upper lobes and a thick-walled cyst in the lower left lung zone in a field of fibrotic lesions in a 60-year-old patient diagnosed with idiopathic pulmonary fibrosis.

Figure 3

Progressive transition HRCT pattern of CPFE. The typical distribution: predominant pattern of centrilobular emphysema in the upper lobes, extending to a panlobular emphysema in the midzones, and an isolated area of centrilobular emphysema in the left lower lobe in the field of subpleural reticular opacities, traction bronchiectasis, and bronchioloectasis in a 59-year-old patient with fibrotic hypersensitivity pneumonitis with a history of 30 pack-years of smoking.

Figure 4

HRCT pattern of emphysema admixed with DIP. Areas of low attenuation (emphysema) are mixed with ground-glass opacities (areas of high attenuation) and periemphysematous thickening.