Noninfectious causes of cavitary pulmonary lesions include the following: Empyema or bulla with air-fluid level Cystic (saccular) bronchiectasis Lung cancer Lung infarction Nodular silicosis nodule with central necrosis Pulmonary embolism Pulmonary sequestration Sarcoidosis Granulomatosis with polyangiitis Rheumatoid lung nodules In an anaerobic infection due to aspiration, chest x-ray classically shows consolidation with a single cavity containing an air-fluid level in portions of the lung that would be dependent when the patient is recumbent (eg, the posterior segments of the upper lobes or the superior or lateral basal segments of the lower lobes).