A 69 year-old male with chronic lymphocytic leukemia presents with cough and foul-smelling sputum. What is the most likely diagnosis?

The presentation of a 69-year-old male with chronic lymphocytic leukemia who exhibits cough and foul-smelling sputum strongly suggests bronchiectasis as the most likely diagnosis. Bronchiectasis is characterized by abnormal and permanent dilation of the bronchi, which leads to a buildup of mucus and subsequent recurrent infections. Patients often present with a chronic productive cough and purulent sputum, which may have a foul odor due to the presence of bacteria such as Pseudomonas aeruginosa or other pathogens commonly involved in lung infections.

In the context of chronic lymphocytic leukemia, the immunocompromised state can lead to increased susceptibility to infections and lung complications, making bronchiectasis a plausible condition. The foul-smelling sputum particularly aligns with increased bacterial colonization, which is common in bronchiectasis.

While tuberculosis and adenocarcinoma can also result in cough and sputum production, they are less likely to present with the characteristic foul-smelling nature of the sputum, making bronchiectasis the more fitting diagnosis in this case. Pulmonary fibrosis typically manifests with a dry cough and respiratory distress rather than producing copious, foul-smelling sputum. Thus, the clinical features and context point towards bronchiectasis as the most