An unusual prenatal manifestation of a huge congenital cystic adenomatoid malformation with favorable perinatal outcome
A 33-year-old primi gravida was referred to our tertiary center at 21+3 weeks of gestation because of a suspected large thoracic mass with ascites. Ultrasonography was performed using the Accuvix A30 (Samsung Medison Co. Ltd., Seoul, Korea) with a 2 to 6 MHz transabdominal probe. The initial ultrasonography revealed a huge hyperechoic and well-defined mass in the right lung, occupying approximately three-quarters of the thoracic volume (). A cystic lesion of 25 mm in diameter was located centrally within the mass and this mass was supplied by the pulmonary artery (). The fetus was diagnosed with mixed CCAM. The heart was forced to the left side of the thoracic cavity, which made the left lung nearly invisible on the ultrasonography. The fetus was hydrophic, with massive ascites and scalp edema, and left cardiac function was decreased. No other abnormalities were found.\nFollowing extensive counseling on the prognosis and the possibility of intrauterine death, the parents chose to continue the pregnancy. The parents also did not wish to perform fetal karyotyping. Because of massive ascites, we decided to perform the abdomino-amniotic shunting immediately. The patient was admitted at 21+3 weeks of gestation and abdomino-amniotic shunting was performed. After successful shunting, the ascites disappeared () and the fetal hydrops was also resolved two weeks following the shunting. Serial ultrasonographs showed an alleviation of the mediastinal shifting, a decrease in mass size, and the appearance of the left lung (). Cardiac function also improved.\nA follow-up ultrasound at 36+1 weeks of gestation demonstrated retarded fetal growth with oligohydramnios, and therefore we decided to deliver the baby. The mother delivered an 1,890 g female fetus by Cesarean section at 36+3 weeks of gestation. Initial crying was good and the Apgar score were 7 and 8 at 1 and 5 minutes, respectively. However the baby developed respiratory distress soon after birth and was placed on a mechanical ventilator. Chest computed tomography (CT) showed a large solid mass with an internal cystic lesion in the right middle to lower lung, suggestive of CCAM (). On postnatal day 5, a lobectomy of the right middle and lower lung was performed. A pathology report confirmed the diagnosis of mixed CCAM. The baby was doing well without any respiratory symptoms at one month of follow-up.