Alveolar capillary dysplasia associated with duodenal atresia: ultrasonographic findings of enlarged, highly echogenic lungs and gastric dilatation in a third-trimester fetus.

We report a case of alveolar capillary dysplasia, wherein duodenal atresia was diagnosed during the third trimester. A 36-year-old mother was referred to our hospital for polyhydramnios at 31 weeks' gestation. Duodenal atresia was suspected from the ultrasonographic findings, which showed gastric dilation. Other findings noted were enlarged, highly echogenic lungs, a spherical heart and an increased lung-thorax transverse area ratio. A male infant was born at 37 weeks' gestation. The findings of serial radiography of the infant's upper gastrointestinal tract were compatible with the diagnosis of duodenal atresia; however, he developed persistent pulmonary hypertension of the newborn eight hours after birth and died at five days of age. The autopsy revealed alveolar capillary dysplasia and duodenal obstruction. We propose that the detection of duodenal atresia should prompt the physician to conduct a thorough ultrasonographic examination to rule out associated anomalies, such as alveolar capillary dysplasia, which can be detected by the presence of highly echogenic lungs.