Lung abscess (collection of pus)

Chest | Pulmonology | Lung abscess (collection of pus) (Disease)


A lung abscess, or pulmonary abscess, is a localized collection of pus associated with necrosis of the lung tissue. The abscess is basically a cavity that forms in the lung tissue, walled off by fibrous tissue and filled with pus, cellular debris, microbes and white blood cells. A lung abscess is the consequence of infectious microorganisms, particularly bacteria, entering or invading the lung tissue. It may occur either as a solitary abscess (single) or multiple abscesses.

Causes and Risk factors

Any pathogen can cause abscess formation but anaerobic bacteria are the most likely microorganisms to do so. If the abscess develops in an otherwise healthy lung and respiratory tract, then it is considered as a primary abscess. It can however develop as a complication of some underlying lung pathology – secondary abscess.

The size of the abscess can vary from a few millimeters in diameter to several centimeters (up to 5 to 6 cm). The abscess may communicate with an air passage (usually the bronchus) and then partially drain and become filled with air. The pus in this case is expectorated (sputum). However, if the abscess extends into the pleural cavity, possibly via a fistula, then it may lead to empyema (fluid around lungs – pus).

Diagnosis and Treatment

To identify the abscess imaging tests are undertaken. While treatment consists in intravenous antibiotics, most abscesses will have to be drained either through the skin (percutaneous) or surgically. Small abscesses usually go away with antibiotics. ...