What are the differential diagnoses for cavitating lesions on chest xray?
Malignancy (primary of secondary), infection (S. aureus, Klebsiella, pseudomonas, fungal infection, tuberculosis, infected bullae, septic emboli), autoimmune (vasculitis such as Wegener's granulomatosis), non-infective (granulomas, pulmonary infarct, pneumatocele) and congenital causes (e.g. bronchogenic cysts).
Right middle lobe consolidation with an associated cavitating lesion and air bronchogram. There is a small right sided pleural effusion. The remainder of the lung fields are unremarkable. There are no abnormalities of the mediastinal structures, bones or soft tissues.