This case has two main findings:
- obvious right upper lobe pneumonia
- less obvious free gas under the right hemidiaphragm
How are the two findings related? The patient was 24 hours post-operative for appendectomy, and had developed respiratory symptoms, most likely an aspiration pneumonia given the history and that the right upper lobe is affected.
This case demonstrates a potential satisfaction of search error, where the on spotting the right upper lobe pneumonia further abnormalities are not sought.