A 55-year-old man with poor dentition and a history of heavy alcohol use presents with 2 weeks of fever, foul-smelling sputum, and weight loss. CT shows a thick-walled cavity with an air-fluid level in the superior segment of the right lower lobe. The most likely mechanism producing this lesion's location is:

• A Hematogenous seeding from tricuspid valve endocarditis
• B Aspiration of oropharyngeal contents while recumbent, with gravity-directed deposition ✓
• C Direct extension from a subdiaphragmatic abscess through the diaphragm
• D Endobronchial obstruction by a centrally located squamous cell carcinoma

Explanation

Aspiration lung abscesses develop when oropharyngeal anaerobes are aspirated; in a recumbent person the aspirate gravitates to the dependent segments, namely the superior segment of the lower lobes and the posterior segment of the upper lobes, explaining this lesion's site. Hematogenous abscesses from endocarditis are typically multiple and peripheral, subdiaphragmatic extension produces basal lesions, and post-obstructive abscesses follow a visible central mass.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.