Presentation
Progressive shortness of breath over the past week.
Patient Data
Age: 55 years
Gender: Female
From the case:
Pleural effusion
Frontal

Large left sided pleural effusion.
The meniscus is well demonstrated on the superolateral aspect indicating fluid in the pleural space.
The effusion is causing midline shift.
Case Discussion
A simple x-ray of a common pathology with classical signs and some sound teaching principles.
One cause of opacification of the hemithorax is a pleural effusion.
When large it will 'push' the mediastinum away from it.
It will also have meniscus indicating fluid in the pleural space.
Consolidation, collapse and a pneumonectomy will not have these features.