Permanent dilation of bronchioles and bronchi caused by chronic necrotizing infections best describes?

• A. Bronchiectasis
• B. Bronchiolitis
• C. Emphysema
• D. Atelectasis

Answer: (A)

Permanent dilation of the bronchi and bronchioles due to chronic necrotizing infections is bronchiectasis. In this condition, repeated or ongoing infection and inflammation erode the muscular and elastic components of the bronchial walls, so the airways lose their normal structure and become irreversibly dilated. This creates a vicious cycle: infection inflames and damages the walls, the dilation impairs clearance of secretions, and retained mucus fosters more infection.

Clinically, patients often have a chronic productive cough with large amounts of purulent, sometimes foul-smelling sputum, and they may have recurrent respiratory infections. On imaging, bronchiectasis shows visibly widened airways with thickened walls; CT is particularly characteristic, showing dilated bronchi that may appear as ring-like or tram-track markings.

Bronchiolitis involves inflammation of the small airways and is not defined by permanent dilation of the larger bronchi and bronchioles. Emphysema is the destruction of alveolar walls with enlargement of airspaces, not dilation of the conducting airways from necrotizing infection. Atelectasis is lung collapse due to obstruction or compression, not permanent airway dilation from chronic infection.