Abstract
Congenital pulmonary airway malformations (CPAMs) are the most prevalent congenital lung lesions, yet their postnatal trajectory remains heterogeneous. Although many antenatally detected macrocystic lesions remain clinically silent, rapid postnatal enlargement can precipitate tension physiology, air-leak syndromes, and secondary pulmonary hypertension - events that mandate urgent departure from elective surgical timetables. We report a term female infant with a right-sided type 1 CPAM diagnosed by 20-week ultrasound. Despite an initial asymptomatic course, the lesion expanded abruptly at four weeks of age, producing severe hyperinflation, bilateral tension pneumothoraces, ventilator dependence, and refractory pulmonary hypertension. Optimization with high-frequency oscillatory ventilation, inhaled nitric oxide, dual oral vasodilator therapy, and chest-tube decompression facilitated physiological stabilization. Definitive management proceeded in two stages: cyst decompression and wedge resection at six weeks, followed by completion of middle lobectomy at 12 weeks. Postoperative complications - including a transient pulmonary hypertensive crisis, Stenotrophomonas maltophilia ventilator-associated pneumonia, and hypoxic-ischemic seizures - were managed successfully with targeted pharmacologic and supportive measures. This case underscores three practice points: (1) ostensibly quiescent CPAMs warrant vigilant surveillance for early indicators of mass-effect decompensation; (2) short, deliberate delays in definitive resection can be justified to optimize respiratory mechanics and pulmonary vascular resistance, thereby reducing perioperative risk; and (3) staged surgical intervention, coupled with multidisciplinary critical-care support, can restore normal cardiopulmonary physiology and permit discontinuation of pulmonary vasodilators within the first year of life.