Masson bodies are seen in:: (A) Usual interstitial pneumonia, (B) Non-specific interstitial pneumonia, (C) Cryptogenic Organizing Pneumonia, (D) Hyaline membrane disease
Answer is C. Masson bodies is characterized by involvement of alveolar space. Alveolar space & bronchioles have collection of Fibroblast. It is seen in patient with Cryptogenic Organizing Pneumonia. Cryptogenic organizing pneumonia aka bronchiolitis obliterans organizing pneumonia. Usual interstitial pneumonia - associated with Idiopathic pulmonary fibrosis .