Fig. 1: First CXR showing right hyperlucency with left-ward herniation and compression of left lung.
A new chest x-ray showed the previously noted hyperlucency occupying the entire right hemithorax and herniating to the left and compressing the left lung. (Fig 2) The trachea was deviated to the left and no lung markings were visible on the right. The differential diagnoses included congenital pulmonary airway malformation (CPAM), congenital lobar over inflation (CLO) and vascular sling. Acquired causes like foreign body and extrinsic lymph node compression, with ball-valve effect and unilateral airway trapping were also entertained. A contrasted CT confirmed the right-sided hyperlucent lung with herniation to the left and left tracheal deviation. In addition, a small compressed right lung could be visualised on the axial lung field view. (Fig 3) The left lung was also compressed. Mediastinal lymph nodes and vascular rings were excluded on mediastinal windows. His blood work-up was unremarkable.