Left Upper Lobe Atelectasis
- endobronchial cancer, rarely a metastasis
- endobronchial mucus plug (eg asthmatics, bronchopulmonary aspergillosis)
- constriction of bronchus by tumor (small cell, lymphoma), bronchostenosis
- endobronchial tuberculosis or other granulomatous infections (fungus)
CXR Findings: Can be subtle and easy to miss especially when only partial atelectasis is present. Typically, presents as an ill-defined haziness/density in left upper lung with obscuration of the aortic arch.
Other findings on chest x-ray include elevation of the left mainstem bronchus, variable elevation of the left hemidiaphragm and typical retrosternal line seen on lateral view.
This radiograph is actually of a patient with bilateral upper lobe atelectasis.
Look at both PA and lateral views
Look for ancillary findings (eg. adenopathy, TB, underlying airways disease)
Follow chronology of findings if old films available
"Aunt Sophies": Many especially if atelectasis partial
- Lung tumor
- Granulomatous infections eg tuberculosis
- Lung contusion
- Rarer entities: COP, eosinophilic lung disease, pulmonary emboli