Cystic translucency seen under the pleura of the upper lobes of both lungs Usually, cystic translucency found on CT images of the lungs is usually a cystic lesion of the lungs, and most of the lung diseases can be manifested as cystic translucency, such as congenital cysts of the lungs, pulmonary pustules, honeycomb lungs, as well as Langerhans’ cell histiocytosis, and lymphatic smooth muscle myelomatosis. 1. Congenital pulmonary cysts: If several cystic lucencies are found on the lung CT image, congenital pulmonary cysts may be considered. 2. Pulmonary alveoli: If the CT examination shows few inflammatory infiltrating lesions in the adjacent lung tissues, which are manifested as cystic translucent shadows, combined with the history of emphysema, pulmonary alveoli may be present. 3. Cellular lung: CT examination reveals multiple subpleural cystic translucent shadows accompanied by bronchiectasis, as well as the presence of pulmonary failure, manifested by dyspnea may belong to the manifestation of cellular lung. 4. Langerhans’ cell histiocytosis: this disease is associated with a history of smoking for many years, and multiple bronchiolar nodules and cystic cavities in both lungs can be seen on CT. 5. Lymphangioleiomyomatosis: CT examination reveals diffusely distributed cystic structures in both lungs, and in the presence of metastases, cystic translucency. The cystic translucent shadow under the pleura of the upper lobes of both lungs may also be due to other reasons, you can go to the respiratory department and thoracic surgery department of the local hospital to consult and listen to the opinions of professional doctors, the above views are for reference only.