A term male neonate is delivered via emergency caesarean section following a pregnancy complicated by reduced fetal movements in the third trimester. The mother had a history of prolonged rupture of membranes several days prior to delivery and antenatal scans had noted reduced amniotic fluid volume.

At birth, the baby requires immediate respiratory support. He has severe respiratory distress with poor chest expansion.

On examination in the resuscitaire:

Marked intercostal recession

Poor air entry on one side

Heart sounds appear displaced

A chest radiograph is performed.

It demonstrates:

A completely opaque hemithorax

Narrowed intercostal spaces with rib crowding

Which of the following is the most likely underlying diagnosis?