A routine obstetrical ultrasound done to a healthy 27-year-old woman G1P0, showed a single fetus with severe polyhydramnios and a huge cystic-liquid, left abdomino-thoracic unilocular mass. The mediastinum appeared to displaced to the right and a left lung hypoplasia was suspected.

An ultrafast MRI was then performed:

The following differential diagnosis were entertained:

1. Left congenital diaphragmatic hernia with a huge gastrointestinal abdominothoracic duplication (giant duodenal duplication ?)

2. A neurenteric cyst, but neither vertebral anomalies were detected nor any connection between the spine and gut

3. Congenital cystic adenomatoid malformation of the left lung Type 1, but the image was not typical for this diagnosis

4. Thoracic lymphangioma (hygroma), but unilocular cyst made this diagnosis unlikely.

5. No other associated anomalies were detected and we assumed this as a high fetal risk situation due to pulmonary hypoplasia.

The following management was then discussed:

1. Amnioreduction: to prevent preterm labor and

2. Puncture of the abdomino-thoracic mass followed by insertion of a Harrison´s catheter to drain the cystic mass toward the amniotic cavity. We wondered what would be the result and consequences if the mass resulted to be an enteric duplication of some type. We assumed that the nature of the liquid eventually obtained by puncture, would give us important data to achieve a diagnosis.

The family refused intervention and went back home, far away from our center. Preterm labor started before arriving to their province and the newborn died soon after birth. At autopsy the large cystic image resulted from a left congenital diaphragmatic hernia with complete left diaphragmatic agenesis and a thoracic positioning of a hugely dilated stomach with an axial volvulus. The gastric outlet was located in the upper thorax and a pyloric atresia was present.

The final diagnosis was thus congenital diaphragmatic hernia and Pyloric atresia

Discussion

The gastric outlet obstruction (pyloric atresia) finally explained the huge entrapment of liquid in the dilated stomach located in the thorax. Intrestingly, the volvulus prevented reflux out of the stomach. The spleen was also located high in the thoracic cavity but neither the liver nor the small and large intestine could invade the thoracic cavity. The massive displacement of the fetal mediastinum provoked a severe bilateral lung hypoplasia which ultimately would have been made postnatal survival of this baby very unlikely, even in a third degree neonatal intensive care unit.

We do not know if the proposed interventional management would have solved the fetal situation in terms of the lung hypoplasia. We presume a catheter dislodgement would have been a probable complication. Theoretically, the decompression and drainage of the stomach would have be equivalent to the deflation of those balloons used in lambs by DeVries and Harrison to create the initial experimental animal model of congenital diaphragmatic hernia back in the early 80´. Also theoretically, drainage of the stomach would have been made possible the reversion of the lung hypoplasia between the 26th. week and term. To our knowledge, the association of a pyloric atresia and a congenital diaphragmatic hernia , has not frequently been observed.