Two cases of pleuroparenchymal fibroelastosis diagnosed with transbronchial lung biopsy

Idiopathic pleuroparenchymal fibroelastosis (PPFE) is a rare subset of idiopathic interstitial pneumonias (IIPs). Here we present two patients with PPFE in which the histology was confirmed with transbronchial lung biopsy (TBLB). The 25-year-old and 64-year-old men were both slender with a long history of pulmonary upper lobe fibrosis and a marked restrictive impairment. Although the imaging findings supported the diagnosis of PPFE, surgical lung biopsy (SLB) seemed to be needed to identify fibroelastosis for the definite diagnosis. However, we selected TBLB instead of SLB because of their general condition and the risk such as prolonged pneumothorax after TBLB. TBLB specimens in both patients showed aggregates of elastic fibers in the submucosa that were essential clues for the histological diagnosis of PPFE. TBLB may be an alternative tool for the histological diagnosis of PPFE, although a multidisciplinary discussion is necessary for the final diagnosis of PPFE as a clinicopathological entity.