1 Assistant Professor, Department of Medicine, University of Colorado
Objectives
- Identify distinguishing features of a lung abscess.
- Use a mnemonic to generate a differential for cavitary lung lesions.
Teaching Instructions
Plan to spend 5-10 minutes familiarizing yourself with the animations of the powerpoint and the key findings of this chest X-ray.
Present the image either by expanding the window (bottom right) in a browser or downloading the PowerPoint file. Have the image pulled up in presenter mode before learners look at the screen to avoid revealing the diagnosis. Advance through the animations to prompt learners with key questions and to reveal the findings, diagnosis and teaching points. Read the following beforehand in preparation:
CXR Interpretation: Bilateral upper airspace disease with a rounded thick-walled cavity in the left upper lobe surrounded by interstitial markings and ground-glass opacities.
Clinical Diagnosis: Left upper lobe lung abscess from actinomyces, confirmed by bronchoalveolar lavage.
Mneumonic for lung cavitations: CAVITY
C:Â cancer, most commonly:
– Squamous cell carcinoma (SCC)
– cavitary pulmonary metastasis(es)
A:Â autoimmune; granulomas from
– Granulomatosis with polyangiitis
– Rheumatoid arthritis (rheumatoid nodules) etc.
V: vascular (both bland and septic pulmonary emboli)
I:Â infection (bacterial/fungal)
Lung abscess / cavitating PNA (acute-subacute)
Septic pulmonary emboli (acute-subacute)
Pulmonary tuberculosis
T:Â trauma –Â pneumatoceles (air-filled cavity in the lung)
Y:Â youth (congenital causes of pulmonary cavitation)
Presentation Board
Take Home Point
- Lung abscesses are classically characterized by a thick, rounded wall with surrounding hazy opacities and commonly have an air-fluid level.
- There is a limited differential for cavitary lung lesions. A useful pneumonic is CAVITY:
Cancer (*SCC)
Autoimmune (*GPA)
Vascular
Infection (bacterial/fungal)
Trauma
Youth (congenital)
References
McLoud, Boiselle, & Boiselle, Phillip M. (2010). Thoracic radiology : The requisites (2nd ed., Requisites in radiology). Philadelphia: Mosby/Elsevier.
