Original Research: Diffuse Lung DiseaseTransbronchial Cryobiopsy in Diffuse Parenchymal Lung Disease: Retrospective Analysis of 74 Cases

BACKGROUND: Diagnostic evaluation of patients with diffuse parenchymal lung disease (DPLD) is best achieved by a multidisciplinary team correlating clinical, radiological, and pathologic features. Surgical lung biopsy remains the gold standard for histopathologic diagnosis of idiopathic interstitial pneumonias. Emerging data suggest an increasing role for transbronchial cryobiopsy (TBC) in DPLD evaluation. We describe our experience with TBC in patients with DPLD. METHODS: We retrospectively reviewed medical records of patients with radiographic features of DPLD who underwent TBC at Mayo Clinic in Rochester, Minnesota from June 2013 to September 2015. RESULTS: Seventy-four patients (33 women [45%]) with a mean age of 63 years (SD, 13.8) were included. The mean maximal diameter of the samples was 9.2 mm (range, 2-20 mm [SD, 3.9]). Themedian number of samples per procedure was three (range, one to seven). Diagnostic yield was 51% (38 of 74 specimens). The most frequent histopathologic patterns were granulomatous inflammation (12 patients) and organizing pneumonia (OP) (11 patients), resulting in the final diagnoses of hypersensitivity pneumonitis (six patients), cryptogenic OP (six patients), connective tissue disease-associated OP (three patients), drug toxicity (three patients), infection-related OP (two patients), sarcoidosis (two patients), and aspiration (one patient). Other histopathologic patterns included respiratory bronchiolitis (three patients), acute fibrinous and organizing pneumonia (two patients), desquamative interstitial pneumonia (1 patient), diffuse alveolar damage (one patient), pulmonary alveolar proteinosis (one patient), amyloidosis (one patient), eosinophilic pneumonia (one patient), necrotizing vasculitis (one patient), bronchiolitis with food particles (one patient), and malignancy (three patients). Pneumothorax developed in one patient (1.4%), and bleeding occurred in 16 patients (22%). CONCLUSIONS: Our single-center cohort demonstrated a 51% diagnostic yield from TBC; the rates of pneumothorax and bleeding were 1.4% and 22%, respectively. The optimal use of TBC needs to be determined.