Heterogeneity in combined pulmonary fibrosis and emphysema

Background: Combined pulmonary fibrosis and emphysema (CPFE) is a unique disorder described in several case series of upper lobe emphysema associated with lower lobe fibrosis. Patients with this entity have relatively preserved lung volumes and spirometry but marked reductions in diffusing capacity on pulmonary function testing. Smoking appears to be the predominant risk factor for this disorder. Usual interstitial pneumonia has been the most common histological pattern of interstitial lung disease described on biopsy in the literature.

Objectives: To characterize the clinical, imaging and pathological features of a cohort of patients with CPFE.

Methods: Retrospective review of electronic medical record data, radiological imaging, and available lung biopsy specimens for a series of 10 patients with CPFE at the Providence VA Medical Center, Providence, R.I., USA.

Results: We describe a series of 10 patients with CPFE. All had severe reductions in diffusing capacity out of proportion to their lung volumes and spirometry. All had predominantly upper lobe emphysema on computed tomography; 8/10 had lower lobe subpleural reticular abnormalities and honeycombing, while 2 had lower lobe ground glass changes on imaging. These 2 patients demonstrated a pattern of interstitial lung disease on biopsy characterized by intra-alveolar macrophage accumulation in association with marked alveolar septal fibrosis, consistent with a variant form of desquamative interstitial pneumonia with extensive fibrosis.

Conclusions: The imaging findings and pathology in patients with CPFE are heterogeneous.