Identification of the pathological pattern by transbronchial lung cryobiopsies in patients with fibrosing diffuse parenchymal lung disease

Background: Specimens from transbronchial lung biopsies lack sufficient quality due to crush artifact and are generally too small to identify any pathological pattern for diagnosis of fibrosing diffuse parenchymal lung disease (DPLD). Flexible cryoprobes have been shown to be useful for obtaining more large biopsy samples of lung parenchyma bronchoscopically in patients with DPLD. Objectives: The purpose of this prospective study was to identify the pathological pattern by transbronchial lung cryobiopsy (TLC) using flexible cryoprobe in patients with clinical and radiographic features compatible with fibrosing DPLD and/or chronic Idiopathic Interstitial Pneumonia (IIP) Results Biopsies obtained from 40 patients were evaluated. Adequate cryobiopsies specimens were available in 39 of 40 patients. The average size of cryobiopsies was 6.0 x 4.2 mm. Crush artifacts were not seen. In 34 cases (85%) TLC identified a pathological pattern and contained features to suggest a Usual Interstitial Pneumonia pattern (ie. at least 2 of three pathologic features of UIP present; ie. patchy interstitial fibrosis, fibroblast foci and/or honeycomb changes) in 21 cases; Nonspecific Interstitial Pneumonia pattern in 8 cases; Organizing Pneumonia pattern in 2 cases; Desquamative Interstitial Pneumonia pattern in 1 case; Eosinophilic Pneumonia pattern in 1 case; bronchiolitis pattern in 1 case. In 6 cases (15%) a pathological pattern was not identified. Conclusions In this prospective study the use of the TLC may allow to identify a pathological pattern in patients with clinical and radiographic features compatible with fibrosing DPLD and/or chronic IIP.