What are some common infections that cavitate?
Infectious cavitary lung disease can be related to either pneumonia or septic emboli. Septic emboli are the result of hematogenous dissemination of infection. The source is usually extrathoracic with common locations including infected cardiac valves or indwelling venous catheters. The appearance of septic emboli is usually of multiple cavitating and noncavitating nodules, typically 1 to 3 cm in size, often peripheral in location. These nodules may demonstrate the “feeding vessel” sign, where one can see a pulmonary arterial branch extend to the lesion. Septic emboli, like thrombotic emboli, can lead to areas of pulmonary infarction. Radiographically, pulmonary infarcts appear as peripheral wedge-shaped areas of opacity, which may have areas of central clearing.
Pneumonias that cavitate are usually bacterial, fungal, or mycobacterial in etiology. Some common bacterial pneumonias include Staphylococcus aureus , Klebsiella pneumoniae , and polymicrobial infections from oropharyngeal aspiration.