Gross & microscopic appearance	Pathologic basis of disease	Clinical correlation	
Gross:
•	Cavity in the lung with necrotic debris unless drained by bronchial tree.
•	Wall generally irregular & shaggy.
•	Most likely located in right lung if secondary to inhalation.
•	May be anywhere if sequel to bronchopneumonia or septic emboli.

Microscopic:
•	Destruction of pulmonary parenchyma.
•	Exudate of inflammatory cells.
•	Fibrin deposits in between normal lung tissue.	Etiology:
•	Inhalation of infected material from larynx or pharynx.
•	Aspiration of stomach contents.
•	Obstruction of a bronchus by tumor growth or foreign body.
•	Infection of pre-existing cavities, e.g. in tuberculosis or bronchiectasis.
•	Trauma
•	Pneumonia: abscess is most likely to occur in debilitated persons with bronchopneumonia	Symptoms:
•	Cough with purulent sputum & pain.
•	Fever
•	Weight loss

Sequelae:
•	Small abscesses may heal.
•	Subpleural abscesses may extend to pleural cavity to cause empyema.
•	Bronchopleural fistula resulting in pyopneumothorax.
•	Erosion of large pulmonary vessel: fatal hemorrhage.
•	Septic embolism
•	Secondary amyloidosis.
•	Blood spread leads to meningitis or cerebral abscess.