Lung Abscess: Etiology, Gross and Microscopic Appearance, and Complications

Pathogenesis of Lung Abscess: Mechanism of Formation

A lung abscess is a localized collection of pus within the lung parenchyma, commonly caused by infectious agents.

Etiology

Common causes include bacterial infections such as Staphylococcus aureus, Klebsiella pneumoniae, and Streptococcus species.

Gross Appearance

• Necrotic lung tissue with cavitation
• Purulent exudate within the cavity
• Possible hemorrhagic borders

Microscopic Appearance

Histologically, lung abscesses exhibit:

• Necrotic debris
• Neutrophilic infiltration
• Fibrotic walls in chronic cases

Complications

Potential complications of lung abscess include:

• Bronchopleural fistula
• Sepsis
• Empyema formation