Apical pleural cap
Apical pleural cap refers to a curved density at the lung apex seen on chest radiograph.
Epidemiology
The frequency of apical pleural thickening increases with age 3.
Pathology
It arises from a number of causes:
-
pleural thickening/scarring
- idiopathic: chronic ischemic etiology is favored for most cases 4
- secondary to previous apical infection: typically pulmonary tuberculosis
- radiation fibrosis
- pleuroparenchymal fibroelastosis
- may be present in up to 10% of radiographs 2
- Pancoast tumor
- hematoma
- thoracic aortic injury 5
- upper thoracic spine injury
- fractured 1st rib
- lymphoma: extending from neck/mediastinum
- abscess within the neck/mediastinum