Abstract
One of the idiopathic respiratory tract inflammation is cryptogenic organizing pneumonia (COP). Most patients are symptomatic for <2 months and have a clinical presentation that resembles community-acquired pneumonia. The diagnosis of COP requires histopathologic identification of a predominant pattern of organizing pneumonia and the exclusion of any possible cause. In the patient described herein with interstitial pulmonary disease, the diagnosis of COP was achieved by fiberoptic bronchoscopy. The pathologic findings disclosed bronchioles, alveolar ducts, and alveoli infiltrated with mononuclear cells. The lumina were obliterated with fibroblasts and loose granulation tissue. Corticosteroid treatment resulted in significant improvement. In our patient, the only significant finding was profound Type I respiratory failure without significant raised inflammatory markers. Transbronchial biopsy was a key in making a diagnosis of our patient, as the patient was unwell to undergo video-assisted thoracoscopic surgery.