Histopathological aspects of usual interstitial pneumonia in patients with systemic connective tissue diseases.

Five cases of patients with systemic connective tissue diseases (CTD) who developed connective tissue disease-associated interstitial lung disease (CTD-ILD) with progressive pulmonary fibrosis (PPF) are reported here. Unspecified ILD was diagnosed using high-resolution computed tomography (HRCT). Histologically, all cases were usual interstitial pneumonia (UIP) with findings of advanced (3/5) to diffuse (2/5) fibrosis, with a partially (4/5) to completely (1/5) formed image of a honeycomb lung. The fibrosis itself spread subpleurally and periseptally to more central parts (2/5) of the lung, around the alveolar ducts (2/5), or even without predisposition (1/5). Simultaneously, there was architectural reconstruction based on the mutual fusion of fibrosis without compression of the surrounding lung parenchyma (1/5), or with its compression (4/5). The whole process was accompanied by multifocal (1/5), dispersed (2/5), or organized inflammation in aggregates and lymphoid follicles (2/5). As a result of continuous fibroproduction and maturation of the connective tissue, the alveolar septa thickened, delimiting groups of alveoli that merged into air bullae. Few indistinctly visible (2/5), few clearly visible (1/5), multiple indistinctly visible (1/5), and multiple clearly visible (1/5) fibroblastic foci were present. Among the concomitant changes, areas of emphysema, bronchioloectasia, and bronchiectasis, as well as bronchial and vessel wall hypertrophy, and mucostasis in the alveoli and edema were observed. The differences in the histological appearance of usual interstitial pneumonia associated with systemic connective tissue diseases (CTD-UIP) versus the pattern associated with idiopathic pulmonary fibrosis (IPF-UIP) are discussed here. The main differences lie in spreading lung fibrosis, architectural lung remodeling, fibroblastic foci, and inflammatory infiltrates.

Histopathological findings in lung biopsies with usual interstitial pneumonia: Definition of a new classification score for histological fibrotic stages.

The objective of this article is to describe and classify usual interstitial pneumonia (UIP) changes according to their relevance in the pathology of the idiopathic pulmonary fibrosis (IPF) process. In a cohort of 50 patients (25♀, 25♂) with UIP findings, the percentage ratio between fibrotic and preserved parts of the lungs was quantified. Three quantitative stages of fibrotic involvement of the lung parenchyma and concomitant changes were defined. These are initial (≤20%), advanced (21-40%), and diffuse (≥41%) fibrosis of the lungs. Histologically, temporal heterogeneity is predominant with thickened alveolar septa, interstitial fibrosis, and the presence of fibroblastic foci up to mature diffuse fibrosis with honeycomb changes. The finding is accompanied by variably mature lymphocytic inflammation, presence of macrophages, emphysema, bronchioloectasia of the alveoli, bronchiectasis, bronchial muscle wall hypertrophy, hypertrophy of the vessel walls, alveolar mucosa, focal haemorrhage, and hyalinization of the lungs. Pneumocyte hyperplasia, occasionally atypical in appearance with hobnail changes, as well as squamous metaplasia are observed. In the methodically quantified stages of fibrous involvement, 14 subjects were classified (6♀, 8♂) into the stage of initial fibrosis, 21 subjects (11♀; 10♂) into the stage of advanced fibrosis, and 15 subjects (8♀; 7♂) into the stage of diffuse fibrosis.

Unusual pneumoconiosis in two patients with heavy print toner, and paper dust exposure.

Workers in a print shop are exposed to photocopier toner dust and paper dust over a prolonged period of time. However, there are only rare case reports of toner and paper dust induced lung damage in humans. We reviewed our consultation files for a period of 30 years from 1987 to 2018 to look for cases with a diagnosis of giant cell interstitial pneumonia (GIP), printer toner exposure and paper dust exposure resulting in lung disease. There were two cases which met our inclusion criteria. Slides, clinical histories and imaging were reviewed. Both the patients had worked in print shops, and had no history of exposure to hard metals. Patient 1 presented with shortness of breath and cough over several months, while patient 2 was asymptomatic at presentation. Both the patients underwent surgical lung biopsies. Histopathologic examination from both the cases showed a spectrum of pathology, including features of GIP, desquamative interstitial pneumonia, chronic bronchiolitis with lymphoid hyperplasia, and particulate matter consistent with toner. Energy dispersive spectroscopy was performed on one case, and it revealed no cobalt or tungsten particles. The unusual combination of findings is very suggestive that toner particles with or without paper dust exposure were responsible for the pathologic changes in the lungs of these patients. This possibility should be explored further with additional patients who work in print shops where they are exposed to paper dust and paper toner and have signs or symptoms of diffuse lung disease.