Combined unclassifiable interstitial pneumonia and emphysema: a report of two cases.

We herein report two cases of combined pulmonary fibrosis and emphysema (CPFE), whose histological patterns of lung pathology could not be categorized into any subset of idiopathic interstitial pneumonias(IIPs). Case 1 was a 62-year-old man, who presented with dyspnea on exertion and cough. Case 2 was a 51-year-old man with a dry cough. The CT findings of both cases fit the definition of CPFE. Surgical lung biopsies of both patients revealed alveolar septal widening due to collagen deposition, with emphysema and respiratory bronchiolitis mainly in the subpleural parenchyma. These cases suggest that the fibrosis of CPFE includes smoking-related interstitial fibrosis other than the known histological patterns of IIPs.