Congenital cystic adenomatoid malformation of the Lung(CCAM) is characterized by anomalous fetal development of terminal respiratory structures, resulting in an adenomatoid proliferation of bronchiolar elements and cystic formation. CCAM was first described and differentiated from other cystic lung disease in the English literature by Ch'in and Tang in 1949. CCAM is a rare, potentially lethal form of congenital pulmonary cystic disease and the salient features of lesion are an irregular network of terminal respiratory bronchiole-like structures and macrocysts variably lined by pseudostratified ciliated columnar epithelium and simple cuboidal epithelium. Adult presentation of CCAM of the lung is so tare that only 9 cases have been reported in the literature of date. The pathogenesis of CCAM remains disputed and reseachers have variously proposed that the lesion represents a developmental anomaly, hamartoma, or a form of pulmonary dysplasia. Van Dijk and Wagenvoort divided CCAM into three subtypes: cystic, intermediated, and solid. These correspond to types I, II, and III of Stocker. In adults, the evaluation of cystic or multicystic lung disease requires consideration of a differential diagnosis including the acquired lesions of lung abscess, cavitary neoplasm or inflammatory mass, bullous disease, bronchiectasis, and postinflammatory pneumatocele. Congenital lesions such as sequestration, bronchopulmonary-foregut anomalies, and bronchogenic cyst are also encounted. The definitive treatment for CCAM is complete removal of the involved lobe. Partial lobectomy leads to multiple complications, including severe post-operative infection. We report a case of CCAM in a 14-year-old female presentated with a pneumothorax and large bullae, who was treated by surgical remove of the involved lobe.