| Aspergilloma | Varied clinical presentation similar to lung abscess, including cough, weight loss, fever, and hemoptysis; may be asymptomatic; CT reveals soft tissue mass in the lung, usually the upper lobe, separated from cavity wall by airspace (air crescent sign) |
| Bronchiectasis | Chronic, productive cough sometimes accompanied by hemoptysis; CT shows increased airway diameter, lack of peripheral airway tapering, airway constrictions, and ballooned cysts toward the end of the bronchus |
| Localized empyema | Symptoms similar to lung abscess; however, CT helps differentiate the conditions |
| Lung abscess | Localized lung parenchymal necrosis; symptoms include fever, productive cough, foul-smelling or bad-tasting sputum, night sweats, hemoptysis; radiography shows cavitary lesion with fluid level |