Gross & microscopic appearance	Pathologic basis of disease	Clinical correlation	
Gross:
•	Bronchi are grossly dilated throughout their length, some with saccular outpouchings.
•	Intervening lung tissue is much reduced & fibrosed.
•	Pleura is fibrotic & thick with dense adhesion to the chest wall.

Microscopic:
•	Bronchi: production of lymphoid aggregations in the bronchial wall.
•	Alveolar tissue: much of the alveolar tissue adjacent to the dilated bronchi is compressed & obliterated.	Etiology:
•	Infection: most cases are initiated by bronchopneumonia which fails to resolve; in children this may be of primary bacterial origin or a complication of specific infections, e.g. measles, whooping cough.
•	Bronchial obstruction: partial bronchial obstruction by neoplastic growth, enlarged lymph nodes or foreign body, causes retention of secretion & infection leading to localized bronchiectasis.
•	Pneumoconiosis
•	Congenital disease: cystic fibrosis, Kartagener syndrome.

Pathogenesis:
•	Main mechanism is by recurrent inflammation.
•	Destruction of elastic tissue, muscle & cartilage leads directly to bronchial dilation.
•	Spread of infection to pleura causes adhesions and fibrosis of pleura; contraction of fibrous tissues results in bronchial dilation.
•	Chronic coughing leads to rise in bronchial pressure during respiration and expansion of bronchi.	Symptoms:
•	Fever
•	Cough
•	Abundant purulent sputum
•	Obstructive respiratory insufficiency

Complications:
•	Large quantities of secretion are retained in the bronchi & putrefactive bacteria produce a foul smell.
•	Suppuration is common in the cavities resulting in lung abscess & bronchopleura fistula formation.
•	Pyaemia giving rise to brain abscess or meningitis may result from involvement of a pulmonary vein branch by the suppurative process.
•	Destruction of lung tissue leads to pulmonary hypertension & right ventricular heart failure.
•	Clubbing of fingers.
•	Development of amyloid disease, e.g. in kidney.