Cavitation

Cavitation is low-attenuation or lucency within a consolidation, nodule, or mass. While infection is the most common etiology of cavitation, other entities should also be considered. Cavitation of nodules, masses or consolidations is often related to infection, but can also occur in septic embolism, vasculitides, and pulmonary infarction. Aspiration pneumonia may manifest with cavitation and is common in institutionalized patients with altered state of consciousness. Anaerobes and enterobacteria are common etiologic agents. Mycobacterium tuberculosis should always be considered in patients with upper lobe cavitary disease. These patients should be isolated until etiology is proven. Aspergillus spp, nocardia spp, and Pneumocystis jiroveci should be considered in immunocompromised patients. Staphylococcus aureus is the most common cause of septic emboli. In patients without clinical evidence of infection, granulomatosis with polyangiitis and metastatic disease should be considered.