Cryptogenic organizing pneumonia (COP) is a clinicopathologic disease described by Davison and colleagues in 1983. It is idiopathic in nature and is characterized histologically by an alveolar septal lymphocytic infiltrate with type II alveolar epithelial cell hyperplasia at the site of involvement. Clinical features: COP patients are equally distributed by gender, with a ratio of 2:1 non-smokers to smokers. the mean age of onset is 55 years. The patients had a relatively short onset (on average less than 3 months) with varying degrees of cough and dyspnea. Cough and white sputum are usually suspected at the onset of symptoms as a lower respiratory tract infection, but are not certain. Patients are usually treated with at least 1 month or more courses of antibiotics. Common symptoms include persistent weight loss, sweating, chills, intermittent fever, and malaise. Restricted or more widespread popping sounds are often present, with very few signs of solidity and no pestle finger.