UIP

Honeycombing must be present for a diagnosis of UIP by HRCT.45 Honeycombing can be accompanied by traction bronchiectasis or bronchiolectasis, and is subpleural with basal predominance. Less common features accompanying the UIP diagnosis are ground glass opacification on a reticular background, mediastinal lymphadenopathy, small ossified nodules, and features of pleuroparenchymal fibroelastosis at the lung apices. Here we see significant honeycombing, which can be seen in a predominantly subpleural pattern occurring at the bases of the lung as seen in the coronal image. Peripheral reticulation and traction bronchiectasis are present. Note the asymmetric pattern of fibrosis, a hallmark feature of usual interstitial pneumonia not often seen with NSIP.