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

A lung abscess is a localized collection of pus within the lung tissue, often resulting from infection. Understanding its etiology, appearance, management, and prognosis is crucial for effective treatment.

Etiology

Lung abscesses typically develop due to aspiration pneumonia, bacterial infection, or septic emboli. Common causative pathogens include Staphylococcus aureus, Klebsiella pneumoniae, and anaerobic bacteria.

Gross Appearance

On gross examination, lung abscesses appear as necrotic cavities filled with pus. The surrounding lung tissue often shows signs of inflammation and fibrosis.

Microscopic Appearance

Histologically, a lung abscess exhibits central necrosis surrounded by inflammatory infiltrates, primarily composed of neutrophils. Chronic abscesses may show granulation tissue and fibrosis.

Complications

• Sepsis
• Pleural effusion
• Bronchopleural fistula
• Hemoptysis

Management and Prognosis

Treatment Approaches

Management involves a combination of antibiotic therapy, drainage, and supportive care. Broad-spectrum antibiotics targeting anaerobes and aerobes are commonly used.

Outcomes

With timely treatment, most patients recover well. However, delayed intervention can lead to chronic infection, requiring surgical resection.