Picture Prognosis

A 66-year-old woman with longstanding B-cell non-Hodgkin lymphoma and steroid-dependent oral lichen planus develops progressive dyspnea, cough, and severe obstructive ventilatory impairment. Imaging shows hyperinflation and diffuse bronchiectasis. At autopsy, bronchioles demonstrate epithelial detachment, peribronchiolar fibrosis, and luminal narrowing or complete occlusion without organizing pneumonia. What is the most likely diagnosis?