A 26 day old boy presents with cough and coryza for 5 days, and dyspnea for 2 days. His 2 year old brother had an upper respiratory tract infection around 1 week ago. His antenatal, birth, and immediate postnatal histories are unremarkable.
The right upper lobe is collapsed, while the left upper lobe is markedly overdistended. The mediastinum is displaced towards the right.
The echocardiogram is normal.
WBC: 14,200/mm3 (6,000-18,000) Hb: 11.2 g/dL (9.4-13) Platelets: 336,000/dL (150,000-450,000)
The left upper lobe is hyperlucent and grossly hyperinflated, while the left middle and right upper lobes are collapsed. There is significant mediastinal shift towards the right.