morphology

Last reviewed 01/2018

Abscesses may:

• be single or multiple
• affect any part of the lung
• vary in diameter from a few millimetres up

Abscesses due to aspiration are more common on the right, due to the more vertical right bronchus, and most often, are single. Those which develop in the course of pneumonia or bronchiectasis are usually multiple, basal and diffusely scattered. Septic emboli and pyemic abscesses are usually multiple and may affect any region of the lung. Abscesses in the liver usually accompany amoebic lung abscesses.

The cavity may or may not be filled with suppurative debris, depending upon the establishment of a communication with one of the air passages. Continued infection results in large, fetid, green-black, multi-locular cavities with poor margination, so-called "gangrene of the lung".

Histologically, there is suppurative destruction of the lung parenchyma within the central area of cavitation. In chronic cases, fibroelastic proliferation produces a containing fibrous wall.