29th April 2024

A 65-year-old man, a former smoker, presents with a year-long history of progressive breathlessness on exertion and a dry cough.

A 65-year-old man, a former smoker, presents with a year-long history of progressive breathlessness on exertion and a dry cough. He has lost 10 kg over the past six months and reports general fatigue. He has no significant occupational exposures. His physical examination reveals fine crackles at the bases of both lungs. His chest X-ray shows reticular opacities and a high-resolution CT scan reveals honeycombing and traction bronchiectasis, predominantly in the lower lobes.

Which is the most likely diagnosis?