A 20-year-old woman with cystic fibrosis complains of chronic cough with foul-smelling sputum and airway dilatation on chest X-ray. What is the most likely diagnosis?

In this scenario, the presentation of chronic cough with foul-smelling sputum, combined with the airway dilatation observed on chest X-ray, strongly indicates bronchiectasis. This condition is characterized by the abnormal and permanent dilation of the bronchi, which can result from chronic inflammatory processes, infection, or obstruction.

In cystic fibrosis, the thick, sticky mucus that accumulates in the airways can lead to recurrent infections and inflammation, ultimately causing damage to the bronchial walls and resulting in bronchiectasis. The foul-smelling sputum is a common feature due to the presence of specific bacterial infections, particularly with organisms like Pseudomonas aeruginosa.

The chronic productive cough aligns with the classic symptoms of bronchiectasis where thick mucus production is a hallmark. The chest X-ray findings of airway dilatation further support this diagnosis as it depicts the structural changes characteristic of bronchiectasis.

Other options do not align with the specific findings and context of this case. Asthma typically presents with wheezing and variable airflow obstruction, not normally fouling the sputum. Chronic bronchitis is more associated with a productive cough and sputum production unrelated to the structural alterations seen in bronchiectasis. Emphysema primarily involves the destruction