Radial Probe Endobronchial Ultrasound-guided Lung Biopsy for Histopathological Diagnosis of Cryptogenic Organizing Pneumonia

inTrodUcTion Cryptogenic organizing pneumonia (COP) is a distinct type of idiopathic interstitial pneumonia with a response rate of 65–85% on corticosteroid therapy. The difficulty of COP diagnosis is that the clinical features and the radiological findings are nonspecific. The pathological hallmark of organizing pneumonia (OP) needs to be confirmed. It can also occur in a variety of other interstitial pneumonia, infectious diseases, vasculitis, and so on.[1] To increase the pathological reliability, larger and more tissue samples are required. According to the current classification of interstitial lung disease and guidelines, the surgical lung biopsy is recommended and is considered to be the best way of obtaining a representative lung specimen.[2] However, the invasive diagnostic procedures require general anesthesia and also increase the morbidity and mortality risks; therefore, only few patients undergo such biopsy. Thus, safer and more acceptable methods for identifying COP are urgently needed.