Presentation
Cough.
Patient Data
Complete opacification of the right hemithorax with tracheal shift to the right, indicating complete atelectasis within the right lung. The left main bronchus is normally aerated, while the right bronchus is invisible and likely filled with soft tissue. Soft tissue projects into the distal trachea at the level of the carina. The left lung is hyperinflated.
Soft tissue mass occludes the right main bronchus and projects into the trachea. Complete atelectasis right lung and small right pleural effusion.
Case Discussion
The 2 most common causes of hemithorax opacification (white-out) are complete atelectasis of a lung and a massive pleural effusion, but they can often be easily distinguished. Remember that the lung is basically a balloon: normally inflated air-filled lung has normal volume and is black, but deflated (atelectatic) lung has low volume and is opaque (white, soft tissue density). Volume loss results in shift of the mediastinum (heart and trachea) to the side of the white-out. When a massive effusion (usually due to pleural metastases) causes white-out, the additional "stuff" pushes the mediastinum away from the opacified hemithorax. In our case, there is shift of the heart and trachea to the side of the white-out in this patient with lung cancer obstructing the right main bronchus resulting in right lung atelectasis.