nhiều khả năng hiện diện trong thời kỳ chu sinh như là một kết quả của chuyển bình thường của phổi và suy hô hấp. Nếu tổn thương ngoại vi gây tắc nghẽn đường hô hấp, nhiễm trùng postobstructive hay siêu lạm phát thùy phổi | Surgical Management of Congenital Lesions of the Lung 165 most likely to present in the perinatal period as a result of displacement of normal lung and impaired respiration. If peripheral lesions cause airway obstruction postobstructive infections or lobar hyperinflation may develop. When airway blockage is more central significant hyperinflation mediastinal shift and cardiopulmonary compromise may occur. A more unusual presentation in which the cyst exists within the airway wall may present with signs and symptoms similar to an airway foreign body if such a cyst is proximal and enlarges rapidly due to mucus production inflammation or hemorrhage acute airway obstruction may occur. This condition may be hard to diagnose with routine imaging studies as there is no predominant mass. Bronchoscopy may be the only means for diagnosis and treatment of this situation. For the majority of patients however symptoms are less severe and less acute presentation is usually as an older infant or child with complaints of infection or dysphagia. Symptoms of cough wheezing fever or hemoptysis prompt chest roentgenogram which may demonstrate an unusual opacity or lucency postobstructive emphysematous changes or air-fluid level within the cyst Figure 13-3 . A chest radiograph that suggests a mass should be followed by CT scan to verify and localize the mass determine its resectability and to eliminate any nonoperative diagnoses such as pneumonias simple lung abscesses and certain lymphangiectasis. CT scan should demonstrate a cystic structure with a nonenhancing wall it may have an air-fluid level Figures 13-4 and 13-5 . A finding of segmental emphysematous change may warrant bronchoscopy to rule out an airway foreign body especially in the age group in which aspiration is common or extrinsic airway compression. It may be difficult to differentiate between bronchogenic cyst and pulmonary abscess but an indolent clinical course coupled with persistent radiograph findings in the face of
