Diffuse smoking-related lung diseases: insights from a radiologic-pathologic correlation

Abstract

Cigarettes are well-recognized risk factors responsible for the emergence of a variety of pathologic conditions affecting both the airways and the lungs. Smoking-related lung diseases can be classified as chronic obstructive pulmonary disease (COPD) and several types of interstitial diseases, such as pulmonary Langerhans cell histiocytosis, bronchiolitis, desquamative interstitial pneumonitis, acute eosinophilic pneumonia, and interstitial fibrosing lung diseases. The evidence of combined lower lung fibrosis and predominant upper lung emphysema is renowned as a distinct clinical entity, named combined pulmonary fibrosis and emphysema. Although computerized tomography permits an adequate classification and distinction of these diseases, the clinical, imaging, and histological features often overlap and coexist in a single patient. Therefore, a combined radiologic and pathologic approach, in the appropriate clinical setting, is useful for best comprehension and distinction of these entities. Our goals are to describe the imaging features in smoking-related lung diseases and how the pathological manifestations translate on high-resolution computerized tomography.

Keywords: Bronchitis; Emphysema; Fibrosis; Interstitial lung diseases; Smoking.

Fig. 1

Chronic bronchitis. a and b Low-power hematoxylin and eosin stain (H&E) shows an increased number of goblet cells (arrow in a) and hyperplasia of submucosal glands (arrow in b). Hypersecretion of mucus from goblet cells is also visualized

Fig. 2

Bronchial wall thickening in a 79-year-old heavy smoker man. a and b Axial images from a chest CT show thickening of the bronchial walls (arrows). Bronchial wall thickening is an important predictor factor of FEV1 and of the risk of acute exacerbation

Fig. 3

Centrilobular emphysema. Low-power hematoxylin and eosin (H&E) stain shows emphysematous spaces surrounding the terminal bronchioles (arrow; arrowhead in normal parenchyma). Abnormally large airspaces are the result of the destruction of alveolar walls

Fig. 4

Subtypes of CLE according to the Fleischner Society guidelines on HRCT. Axial images in 3 smokers show a trace CLE, with minimal centrilobular lucencies occupying less than 0.5% of a lung zone (arrows); b mild CLE, defined as scattered centrilobular lucencies affecting 0.5% to 5% of a lung zone; and c moderate CLE, with numerous centrilobular lucencies occupying more than 5% of any lung zone

Fig. 5

Subtypes of severe CLE according to the Fleischner Society guidelines on HRCT. a Axial CT image depicts confluent CLE with coalescent centrilobular lucencies without significant distortion of the pulmonary architecture. b Axial and c coronal images show ADE, with panlobular lucencies, distortion of the underlying pulmonary architecture, and hyperexpansion of the lung

Fig. 6

PLE in a 51-year-old man with alpha-1 antitrypsin deficiency. a Axial and b coronal CT images show hyperinflation and lower lobe predominant emphysema, involving the entire secondary pulmonary lobules. Bronquial wall thickening is also depicted (arrows)

Fig. 7

Subtypes of PSE according to the Fleischner Society guidelines on HRCT. a Axial CT shows mild PSE (white arrows) with up to 1 cm juxtapleural well-demarcated lucencies. b Axial CT depicts substantial PSE, defined as cyst-like lucencies or bullae greater than 1 cm adjacent to the pleura. The patient had spontaneous pneumothorax and black arrow depicts a chest drain. Subcutaneous emphysema is also visible in the right thoracic wall

Fig. 8

Bullous emphysema in a 55-year-old man. a Posteroanterior (PA) radiograph shows lucencies in the superior half of the right hemithorax and in the upper left hemithorax. b Axial CT shows upper lobe predominant bullae (asterisks) in the subpleural surface of the right lung. Moderate CLE is also present (arrow)

Fig. 9

Radiologic-pathologic correlation of AEP. a Posteroanterior (PA) radiograph shows bilateral ground-glass opacities and consolidation in the mid-left lung zone. A small left pleural effusion is present. b Axial CT shows peripheral lower lobe consolidations and ground-glass opacities, mainly on the left. c Transthoracic lung biopsy showing eosinophils (black arrow) infiltrating the interstitium and the alveolar spaces; edema (green arrow) and reactive pneumocytes are seen; no necrotizing vasculitis is observed (H&E, × 400)

Fig. 10

Pulmonary Langerhans cell histiocytosis in a 40-year-old man. a Axial CT image shows upper lobe predominance of nodules and cysts of varying wall thickness and irregular margins. Arrow depicts a stellate cellular nodule. b Transthoracic lung biopsy of the nodule highlighted in a shows a nodular aggregate of cells (lymphocytes, eosinophils, plasma cells, and Langerhans cells) centered in bronchioles (arrow) and extending to the interstitium (H&E, × 200). c CD1a immunostaining highlights the Langerhans cells (CD1a, × 100)

Fig. 11

PLCH. a Coronal and b axial CT images in a 30-year-old man show diffuse upper lobe predominant lucencies with basilar sparing. Imaging findings were thought to represent severe confluent emphysema. c Small cysts (asterisk) with nodular aggregates of Langerhans cells in their walls, with a stellate appearance and centered in bronchioles (arrows) (H&E, × 40). d The cells in the nodules have vesicular nuclei and a pale cytoplasm and sometimes with a reniform appearance; some eosinophils are present (H&E, × 400). e CD1a immunostaining highlights the Langerhans cells

Fig. 12

PLCH. Regression of the imaging findings over time (2-year interval), after smoking cessation. a Axial CT image showing cysts with different shapes and sizes diffusely distributed in both lungs. A few cellular and mixed nodules are also present. b Axial CT image at 2-year interval showing almost complete resolution of the imagiological findings

Fig. 13

PLCH. Progression of the imaging findings over time (10-year interval), despite smoking cessation, in a 30-year-old man. a Axial CT image showing diffuse bizarre cysts with walls of varying thickness. b Axial CT image at 10-year interval showing progression of the number and size of the cysts in both lungs

Fig. 14

Differential diagnosis of PLCH. a Sagittal and b axial CT images show a 50-year-old woman with LAM. There are multiple rounded-shaped cysts, with a relatively uniform distribution with no zonal predilection and affecting the lung bases. c Coronal and d axial CT images depict multiple cysts with a lower zone distribution, in a 35-year-old male with Birt-Hogg-Dubé syndrome. The patient had a history of recurrent pneumothoraces

Fig. 15

RB-ILD. a Axial CT image depicts diffuse, ill-defined centrilobular nodules. Due to deteriorating symptoms, the patient underwent lung biopsy. b Excess numbers of alveolar macrophages (arrows) with light brown granules filling the cytoplasm, in a predominant centriacinar location; mild interstitial lymphocytic infiltrate (H&E, × 100)

Fig. 16

DIP in a 58-year-old heavy-smoker man. a Posteroanterior (PA) radiograph shows reticular opacities and ground-glass attenuation in both lungs, predominantly in the lower lung zones. b Axial CT image shows ground-glass opacities with cystic changes in the lower and mid lobes and lingula. Images show well-defined areas of sparing, creating a mosaic attenuation. Mild areas of reticulation and bronchiectasis are also present, signifying fibrosis. c Large numbers of alveolar macrophages with light brown granules filling the cytoplasm (arrow); mild interstitial lymphocytic infiltrate and mild fibrosis (arrowhead) (H&E, × 200)

Fig. 17

Differential diagnosis of RB-ILD. a Axial CT image depicts subacute hypersensitivity pneumonitis (HP) in a 71-year-old woman with a long history of exposition to moldy hay (farmer’s lung). Imaging findings of HP are similar to RB-ILD, which also appears as centrilobular nodules predominantly in the upper lobes (arrow) and patchy areas of ground-glass attenuation. A clinical history is crucial to make the differential diagnosis. b Sarcoidosis in a 37-year-old man. Axial CT image shows diffuse areas of nodularity with peribronchial distribution and also in relation to the subpleural region (arrow). There are also some surrounding ground-glass opacities

Fig. 18

Differential diagnosis of DIP. a Axial and b coronal CT images depict NSIP in a female patient with systemic sclerosis. CT findings show bilateral and asymmetrical ground-glass opacities, with a lower lobe predominance and immediate subpleural sparing. c Axial and d coronal CT images depict pneumocystosis in an immunocompromised patient with HIV. Imaging findings show bilateral ground-glass opacities, predominantly in the lower lobes

Fig. 19

AEF and DIP combined with fibrotic NSIP pattern. a Axial CT image through the upper lobes shows CLE and PLE, associated with reticulation (black arrows) and discrete patchy ground-glass opacities (white arrows). The areas of emphysema within the areas of GGO appear to have more well-defined walls, a finding termed as AEF. b Axial CT at the lower lobes shows GGO with scattered cystic changes, mild reticulation, and bronchiectasis (orange arrow), signifying underlying fibrosis. c Lung transbronchial criobiopsy with uniform thickening of alveolar septa by collagen deposition (black arrows), mild associated inflammation, emphysema, and respiratory bronchiolitis (white arrow) (H&E, × 100)

Fig. 20

Combined pulmonary fibrosis and emphysema (CPFE). a Posteroanterior (PA) radiograph shows right volume loss, diffuse bilateral reticular opacities, and GGO. There are lucencies in the upper lobes (white arrow), signifying bullous emphysema. b Axial and c coronal CT images show centrilobular, paraseptal, and bullous emphysema predominantly in the upper lobes. d Axial image through the lower lobes shows peripheral predominant fibrosis with reticulation, traction bronchiectasis, and honeycombing (black arrow), in a UIP pattern