Bronchiolitis interstitial pneumonitis: a pathologic study of 31 lung biopsies with features intermediate between bronchiolitis obliterans organizing pneumonia and usual interstitial pneumonitis, with clinical correlation

Constrictive Bronchiolitis in Cystic Fibrosis Adolescents with Refractory Pulmonary Decline

“…Although we are not the first group to describe constrictive bronchiolitis in CF (58) or myofibroblast differentiation in chronic fibrotic disease (59), to the best of our knowledge, this article offers the first opportunity to identify the importance of myofibroblast-driven constrictive bronchiolitis in the setting of rapid and refractory CF pulmonary decline.…”

Interstitial Lung Diseases That Are Difficult to Classify: A Review of Bronchiolocentric Interstitial Lung Disease

“…9 The remainder of the reports, however, considered other possible associations, namely, aspiration and inhalation exposure. 9 Notably, the 31 cases reported by Mark and Ruangchira-urai 11 did not have clinical evidence of an association with hypersensitivity. Individual cases of chemical fume exposure, and cases associated with common variable immunodeficiency and transplantation are singlecase reports and appear to be sporadic associations.…”

“…4,5 Some of the difficult to classify ILDs include idiopathic pleuropulmonary fibroelastosis 6 (not discussed here) and a group of ILDs that occur in association with small airway disease. [7][8][9][10][11] LITERATURE REVIEW In terms of idiopathic ILDs showing bronchiolocentricity, efforts to classify the unclassified began only in the early part of the 2000s, with a seminal paper by Yousem and Dacic 7 calling attention to a distinctive form of idiopathic bronchiolocentric interstitial pneumonia (IBIP) that shared histologic similarities with hypersensitivity pneumonitis. In their series of 10 patients, the authors described a centrilobular inflammatory process with small airway fibrosis and inflammation that radiated into the interstitium in a patchy fashion.…”

“…At last follow-up, all patients were alive and 4 had experienced symptomatic improvement. 10 Mark and Ruangchira-urai 11 in 2008 described their experience with 31 patients who had respiratory difficulty leading to open lung biopsy. The biopsy showed a combination of both prominent bronchiolitis and prominent interstitial pneumonitis, which the authors termed BIP, or bronchiolitis interstitial pneumonia (Figure 4).…”

“…Importantly, the authors called attention to the pneumonitis component having inflammation and fibrosis but little or no organizing pneumonia, helping to differentiate BIP from its very similar acronym, BOOP (bronchiolitis obliterans organizing pneumonia), which is now currently referred to as cryptogenic organizing pneumonia, or COP. 11 Of the 31 patients in the series, 19 had follow-up and had received corticosteroid therapy. A total of 7 patients objectively improved, 5 patients had subjective improvement, and 1 patient showed no changes.…”