A cavitary lesion in the lung with surrounding infiltrate in an alcoholic with poor dentition is most consistent with which diagnosis?

• A. Pneumonia with lobar consolidation
• B. Tuberculosis
• C. Bronchiectasis
• D. Lung abscess from aspiration

Answer: (D)

Aspiration of oral contents in someone who is intoxicated or has poor dentition introduces anaerobic bacteria from the mouth into the lung, where a localized infection can evolve into a lung abscess. The hallmark radiographic feature is a cavitary lesion with an air‑fluid level and surrounding inflammatory infiltrate, reflecting a pus-filled cavity with surrounding edema from the infection.

An alcoholic with poor dentition fits this scenario because aspiration risk is high and oral flora include anaerobes capable of forming an abscess. This pattern—cavity formation with surrounding infiltrate—is more characteristic of an abscess than simple pneumonia, which typically shows solid consolidation without a cavity. Tuberculosis can cause cavitation but is not specifically linked to dentition or acute aspiration risk, and bronchiectasis presents with dilated airways and recurrent infections rather than a single cavitary lesion with surrounding infiltrate.

So, the best-fitting diagnosis is a lung abscess due to aspiration.