A 50 yo F with a history of poor dentition presents to the ED with fever and cough productive of yellow sputum x 2 weeks. She has already seen her PCP and finished a course of outpatient antibiotics with no improvement. A CXR is done. What's the diagnosis? (scroll down for answer)

Diagnosis: Cavitary lesion in R middle lobe consistent w/ lung abscess 

• The intraparenchymal air fluid level in the R middle lobe is suggestive of lung abscess (also note surrounding consolidation)
• Primary lung abscesses occur in otherwise healthy individuals and are often related to aspiration or other pulmonary infections; in hospital mortality is 10-15%
• Secondary lung abscesses occur in setting of malignancy, immunosupression, extra pulmonary infection or post surgery and mortality approaches 50%
• Patients typically present with > 2 weeks of cough, fever, pleuritic chest pain, weight loss and night sweats
• Risk factors include: aspiration, dental infection, malignancy, immunosupression, chest trauma, fungal infections, TB, and inflammatory diseases
• CXR shows an area of dense consolidation with an air fluid level inside a cavitary lesion
• Medical management with IV antibiotics will resolve most lung abscesses; approximately 10% will require surgical intervention

References:   Anderson E, Mace SE. Lung Empyema and Abscess. In: Tintinalli JE, Stapczynski J, Ma O, Yealy DM, Meckler GD, Cline DM. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 8e New York, NY: McGraw-Hill; 2016.