Giant Pulmonary Bulla Underlying Bronchopulmonary Dysplasia in a Very Low-birth-weight Infant: a Case Report

Abstract Background: Acquired cystic lung disease is a serious respiratory complication of bronchopulmonary dysplasia in premature infants. Most cases of acquired cystic lung disease underlying bronchopulmonary dysplasia involve pulmonary interstitial emphysema. Although this is a reversible condition, there are a few instances where surgery might be necessary. An accurate diagnosis is important to decide the therapeutic strategy for acquired cystic lung disease. Here, we report a rare case of a giant pulmonary bulla in an infant treated with bullectomy. Case presentation: A male infant born at 23 weeks of gestation with a birth weight of 524 g was initially diagnosed with respiratory distress syndrome. During mechanical ventilatory support, he presented with recurrent pneumothorax and a gradually expanding pulmonary cyst in the right lung. Chest CT at 5 months of age revealed a large cyst located in the subpleural area adjacent to the multiple cystic air spaces. These findings are consistent with the diagnosis of giant pulmonary bulla with pulmonary interstitial emphysema underlying bronchopulmonary dysplasia . At 9 months of age, the giant pulmonary bulla expanded further due to acute bronchitis for which he developed respiratory failure and obstructive shock. This warranted a bullectomy for the giant pulmonary bulla. After the operation, the unresected pulmonary interstitial emphysema lesion did not expand further. He is currently three years old and has no respiratory problems. Conclusions: This case demonstrated that chest CT is useful for providing valuable anatomical information necessary in deciding the treatment strategy for acquired cystic lung disease in infants.