This patient has been followed-up in the respiratory clinics due to her pulmonary Langerhans cell histiocytosis. This is a late follow-up scan in where, different from centrilobular emphysema, the features are those of lung cysts with discrete thin walls. Although present, the nodules are not a distinct finding on this scan but were seen in her old imaging (not shown). The longterm and current smoking history with lung cysts in a predilection for the mid and upper zones make LCH the most likely diagnosis on imaging.