Combined Pulmonary Fibrosis and Emphysema.

Combined pulmonary fibrosis and emphysema (CPFE) is a clinical entity characterized by the combination of upper lobe emphysema and lower lobe fibrosis, the latter owing to various interstitial lung diseases. These patients have a characteristic lung function profile, with relatively preserved dynamic and static lung volumes, contrasting with a significant reduction of carbon monoxide transfer. The pathogenic mechanisms leading to the coexistence of emphysema with fibrosis remain unclear and different theories have been proposed. CPFE is frequently complicated by pulmonary hypertension, acute exacerbations, and lung cancer leading to poor natural history and prognosis. The syndrome of CPFE represents a distinct pulmonary manifestation in the spectrum of lung diseases associated with connective tissue diseases. Currently, there are no established recommendations regarding the management of patients with CPFE. We provide a review on the existing knowledge of CPFE regarding the epidemiology, pathogenesis, clinical manifestations, radiologic appearance, complications, prognosis, and possible treatment options.