Importance of fetal fluid imbalance in congenital cystic adenomatoid malformation of the lung.

Congenital cystic adenomatoid malformation (CCAM) is a regional overgrowth of bronchioles with suppression of alveolar development in fetal and newborn lung. Twelve patients with CCAM were treated. Six premature infants had acute respiratory distress. Prenatal ultrasound was performed in only five patients and was abnormal in all five. Five premature neonates also had patent ductus arteriosus complicating their courses. Six older children presented with recurrent pneumonitis. Radiographs showed asymmetry of the chest and radiolucent masses in all 12 patients. Seven had type I lesions, two had type II lesions, and three had type III lesions. Hydramnios and hydrops were present in three, and hydrops alone was present in one of the six neonates. These four patients died. One other neonate died of respiratory failure and persistent fetal circulation. Seven patients survived for an extended period. Ultrasound makes the prenatal diagnosis of hydramnios and hydrops possible. It is in this group that fetal interventions can be considered. For the remaining patients, surgical intervention is indicated at the time of diagnosis.