Smoking-related interstitial lung diseases: histopathological and imaging perspectives

The present review focuses on the interstitial lung diseases related to smoking. Thus, the pathology and radiology of Langerhans cell histiocytosis, desquamative interstitial pneumonia, respiratory bronchiolitis and respiratory bronchiolitis-associated-interstitial lung disease are considered. The more tenuous association between pulmonary fibrosis and smoking is also discussed.     

Respiratory bronchiolitis, respiratory bronchiolitis-associated interstitial lung disease, and desquamative interstitial pneumonia: different entities or part of the spectrum of the same disease process?

OBJECTIVE: Our objective was to assess high-resolution CT findings of respiratory bronchiolitis, respiratory bronchiolitis-associated interstitial lung disease, and desquamative interstitial pneumonia and to determine whether these three entities could be reliably differentiated by radiologic criteria. MATERIALS AND METHODS: CT scans (1- to 3-mm collimation) were reviewed in 40 patients with pathologically proven respiratory bronchiolitis (n = 16), respiratory bronchiolitis-associated interstitial lung disease (n = 8), or desquamative interstitial pneumonia (n = 16). All patients with respiratory bronchiolitis and respiratory bronchiolitis-associated interstitial lung disease were cigarette smokers, and 85% of the patients with desquamative interstitial pneumonia had a history of smoking. CT scans were independently reviewed by two radiologists who assessed the pattern and distribution of abnormalities. RESULTS: The predominant abnormalities in respiratory bronchiolitis were centrilobular nodules (12 [75%] of 16 patients) and ground-glass attenuation (six [38%] of 16). No single abnormality predominated in the respiratory bronchiolitis-associated interstitial lung disease group; findings included ground-glass attenuation (four [50%] of eight), centrilobular nodules (three [38%] of eight), and mild fibrosis (two [25%] of eight). All patients with desquamative interstitial pneumonia showed ground-glass attenuation, and 10 (63%) of the 16 showed evidence of fibrosis. CONCLUSION: The significant overlap between the CT findings of respiratory bronchiolitis, respiratory bronchiolitis-associated interstitial lung disease, and desquamative interstitial pneumonia is consistent with the concept that they represent different degrees of severity of small airway and parenchymal reaction to cigarette smoke.     

Thoracic involvement of systemic lupus erythematosus: clinical, pathologic, and radiologic findings

Thoracic involvement occurs more frequently in systemic lupus erythematosus than in any other connective tissue diseases, and more than half of patients with the disease suffer from the involvement. Primary intrathoracic manifestations include pleural disease (effusions and/or thickening), acute lupus pneumonitis, subacute interstitial lung disease including bronchiolitis obliterans organizing pneumonia and non-specific interstitial pneumonia with fibrosis, chronic interstitial lung disease of usual interstitial pneumonia, pulmonary hemorrhage, pulmonary vascular disease, small airway disease of bronchiolitis obliterans, and pulmonary arterial hypertension. Secondary intrathoracic manifestations include atelectasis due to diaphragmatic dysfunction, opportunistic pneumonia, drug and oxygen toxicity, aspiration, and pleuropulmonary consequences of cardiac and renal failure.     

Smoking-related lung abnormalities on computed tomography images: comparison with pathological findings

Smoking-related lung abnormalities are now an increasing public health concern. According to the findings of large-cohort studies, approximately 8% of smokers have interstitial lung abnormalities, which are associated with a relatively high risk of all-cause mortality. We reviewed the radiological and pathological findings of smoking-related interstitial lung diseases, such as respiratory bronchiolitis-interstitial lung disease, desquamative interstitial pneumonia, and airspace enlargement with fibrosis. We have also discussed the histological basis of unclassifiable interstitial pneumonia in smokers, which exhibits airway-centered cystic lesions with fibrosis. A variety of radiological findings coexist in the lungs of a smoker. This overlapping of multiple pathological conditions might cause the radiological patterns of diseases to become unclassifiable. Therefore, diagnosis should be performed not on the basis of a single radiological finding, but in a comprehensive manner, by including clinical symptoms and disease behavior. Among interstitial abnormalities in smokers, the usual interstitial pneumonia (UIP) pattern is correlated with a worse prognosis than others. Basal-predominant subpleural reticulation is a clue for accurate diagnosis of UIP, which can be achieved by computer-aided quantitative analysis.     

Idiopathic interstitial pneumonias: CT features

Idiopathic interstitial pneumonias comprise usual interstitial pneumonia (UIP), nonspecific interstitial pneumonia (NSIP), desquamative interstitial pneumonia (DIP), respiratory bronchiolitis-associated interstitial lung disease (RB-ILD), cryptogenic organizing pneumonia (COP), acute interstitial pneumonia (AIP), and lymphoid interstitial pneumonia (LIP). Each of these entities has a typical imaging and histologic pattern, although in practice the imaging patterns may be variable. Each entity may be idiopathic or may be secondary to a recognizable cause such as collagen vascular disease or inhalational exposure. The diagnosis of idiopathic interstitial pneumonia is made by means of correlation of clinical, imaging, and pathologic features. The characteristic computed tomographic (CT) features of UIP are predominantly basal and peripheral reticular pattern with honeycombing and traction bronchiectasis. NSIP is characterized by predominantly basal ground-glass opacity and/or reticular pattern, often with traction bronchiectasis. DIP and RB-ILD are smoking-related lung diseases characterized by ground-glass opacity and centrilobular nodules. COP is characterized by patchy peripheral or peribronchovascular consolidation. AIP manifests as diffuse lung consolidation and ground-glass opacity. LIP is associated with a CT pattern of ground-glass opacity sometimes associated with perivascular cysts.     

Chronic cystic lung disease: diagnostic accuracy of high-resolution CT in 92 patients

OBJECTIVE: The objective of this study was to determine whether the various chronic cystic lung diseases can be differentiated on the basis of the pattern and distribution of abnormalities on high-resolution CT. MATERIALS AND METHODS: High-resolution CT scans in 92 patients with chronic cystic lung diseases (18 with pulmonary Langerhans cell histiocytosis, 18 with pulmonary lymphangioleiomyomatosis, 17 with usual interstitial pneumonia, 16 with lymphocytic interstitial pneumonia, 15 with emphysema, and eight with desquamative interstitial pneumonia or respiratory bronchiolitis interstitial lung disease) were retrospectively assessed by two independent observers without knowledge of the clinical or pathologic data. The observers recorded the abnormalities, the most likely diagnosis, and the degree of confidence in that diagnosis. RESULTS: The two observers made a correct first-choice diagnosis in 148 (80%) of 184 interpretations. The correct diagnosis was made in 100% of interpretations of usual interstitial pneumonia, 81% of desquamative interstitial pneumonia or respiratory bronchiolitis interstitial lung disease, 81% of lymphocytic interstitial pneumonia, 77% of emphysema, 72% of lymphangioleiomyomatosis, and 72% of Langerhans cell histiocytosis. The two observers made a diagnosis with a high degree of confidence in 105 (57%) of 184 interpretations. The confident diagnosis was correct in 98 (93%) of 105 interpretations. CONCLUSION: Although various chronic cystic lung diseases often have a characteristic appearance that allows their distinction on high-resolution CT, considerable overlap exists among the CT findings. Therefore, lung biopsy is often required for a definitive diagnosis.     

Smoking-related interstitial lung diseases: radiologic-pathologic correlation

Smoking-related interstitial lung diseases (SRILD) are a heterogeneous group of entities of unknown cause. These diseases include desquamative interstitial pneumonia (DIP), respiratory-bronchiolitis-related interstitial lung disease (RB-ILD), pulmonary Langerhans’ cell histiocytosis (LCH) and idiopathic pulmonary fibrosis (IPF). High-resolution CT is highly sensitive in the detection of abnormalities in the lung parenchyma and airways. Ground-glass attenuation can occur in DIP and RB-ILD. Whereas DIP is histologically characterized by intra-alveolar pigmented macrophages, RB-ILD shows alveolar macrophages in a patchy peribronchiolar distribution. LCH shows nodular infiltrates on histopathological examination containing varying amounts of characteristic Langerhans’ histiocytes. The HRCT findings are characteristically bilateral, symmetrical and diffuse, involving the upper lobe zones with sparing of the costophrenic angles. The most prominent CT features are nodules (sometimes cavitary) measuring 1 to 10 mm in diameter, cysts and areas of ground-glass attenuation. Pathologically, IPF is characterized by its heterogeneity with areas of normal clung, alveolitis and end-stage fibrosis shown in the same biopsy specimen. High-resolution CT findings consist of honeycombing, traction bronchiectasis and intralobular interstitial thickening with subpleural and lower lung predominance. Since coexisting lesions in the same cases have been observed, a better understanding of the different smoking-related interstitial lung diseases (SRILD) allows a more confident and specific diagnosis.     

支气管血管束异常在肺弥漫性病变诊断中的价值

目的：探讨支气管血管束异常对于肺弥漫性病变的鉴别诊断价值。材料与方法：７２例肺弥漫性病变中，经病理证实１５例，其余５７例均经临床证实。其中肺弥漫性间质性病变３３例，肺弥漫性实质性病变５例，支气管病变１４例，播散性病变２０例。全部病例均做了胸部ＣＴ常规扫描，少数病例同时做了ＨＲＣＴ扫描，每例均由两位主任医师共同观察。结果：支气管血管束异常征象：（１）支气管血管束变细，主要见于肺弥漫性间质性病变和慢性支气管炎。（２）支气管血管束增粗，主要见于肺间质性病变及播散性病变，结节病与癌性淋巴管炎多呈串珠状增粗。（３）支气管血管束显示率增加，主要见于毛细支气管炎及播散性病变。结论：支气管血管束异常是肺弥漫性病变的ＣＴ征象，占８０％，支气管血管束异常无特异性，但呈串珠状增粗多见于结节病及癌性淋巴管炎。特发性肺间质纤维化及慢性支气管炎伴弥漫性间质性病变时，参考横膈位置具有鉴别诊断价值，前者横膈位置正常或升高，后者横膈位置低平。支气管血管束从正常演变到异常，表示病变的发展。     

A 47-year-old patient with longstanding nicotine abuse, increasing dyspnea on exertion and lower and peripheral lung predominant ground-glass opacities

The causal relationship between cigarette smoking and a number of interstitial lung diseases continues to evolve. These "smoking-related interstitial lung diseases" (SR-ILD) are a heterogeneous group of entities which have overlapping imaging findings and which can coexist. The presented case of a patient with smoking history and pulmonary ground-glass opacities demonstrates that thorough knowledge of the various manifestations of SR-ILD is essential for a confident diagnosis.     

47-jähriger Patient mit langjährigem Nikotinabusus, zunehmender Belastungsdyspnoe und diffusen, peripher und basal betonten Milchglastrübungen in der Lunge

The causal relationship between cigarette smoking and a number of interstitial lung diseases continues to evolve. These “smoking-related interstitial lung diseases” (SR-ILD) are a heterogeneous group of entities which have overlapping imaging findings and which can coexist. The presented case of a patient with smoking history and pulmonary ground-glass opacities demonstrates that thorough knowledge of the various manifestations of SR-ILD is essential for a confident diagnosis.     

Respiratory bronchiolitis-associated interstitial lung disease: radiologic features with clinical and pathologic correlation.

PURPOSE: The purpose of this work was to describe the radiographic and CT findings in patients with respiratory bronchiolitis-associated interstitial lung disease (RB-ILD) and to correlate them with clinical, physiologic, and pathologic features. METHOD: RB-ILD was proved pathologically in all 21 patients. Sixteen (76%) patients were current smokers, and five (24%) patients were ex-smokers. The mean cigarette consumption was 38.7 pack-years. Chest radiographs and CT scans were semiquantitatively analyzed and correlated with clinical findings, physiologic measures, and a pathologic score of disease extent. RESULTS: The major radiographic findings were bronchial wall thickening in 16 patients (76%) and ground-glass opacity in 12 patients (57%). The predominant initial CT findings were central bronchial wall thickening (proximal to subsegmental bronchi) in 19 patients (90%), peripheral bronchial wall thickening (distal to subsegmental bronchi) in 18 patients (86%), centrilobular nodules in 15 patients (71%), and ground-glass opacity in 14 patients (67%), None of these CT findings had a significant zonal predominance. Other findings were upper lung predominant centrilobular emphysema (57%) and patchy areas of hypoattenuation (38%) with a lower lung predominance. Radiologic findings were similar in both current and ex-smokers. The amount of ground-glass opacity correlated inversely with arterial oxygen saturation ( r = -0.67, p = 0.04), and the areas of hypoattenuation correlated with alveolar-arterial oxygen gradient ( r = 0.56, p = 0.04). The extent of centrilobular nodules correlated with the extent of macrophages in respiratory bronchioles ( r = 0.53, p = 0.03) and with chronic inflammation of respiratory bronchioles ( r = 0.57, p = 0.02). The extent of ground-glass opacity correlated with the amount of macrophage accumulation in the alveoli and alveolar ducts ( r = 0.56, p < 0.01 and r = 0.54, p = 0.04, respectively). At follow-up CT after steroid treatment and smoking cessation, in nine patients, the extent of bronchial wall thickening, centrilobular nodules, and ground-glass opacity had decreased, but the areas of hypoattenuation had increased (p < 0.05). CONCLUSION: The CT findings of RB-ILD are centrilobular nodules, ground-glass opacity, and air trapping. These radiologic features, in patients with a history of heavy cigarette smoking, may differentiate RB-ILD from other interstitial lung diseases.     

The HRCT appearances of granulomatous pulmonary disease in common variable immune deficiency

Approximately 10% of patients with common variable immune deficiency have systemic granulomatous disease with associated interstitial lung disease. From a population of patients with CVID attending a large tertiary referral clinic for primary immunodeficiency diseases we selected a cohort who had a restrictive defect or impaired gas transfer on pulmonary function testing and/or histologically proven granulomatous disease. HRCT scans of the thorax were reviewed retrospectively in 18 patients by two radiologists. Thirteen patients had diffuse reticulation, which varied from fine to coarse with features of fibrosis. Nodules were found in eight patients. In seven, these were associated with reticulation and in one they were an isolated finding. Bronchiectasis was found as the only abnormality in three and in addition to diffuse reticulation or nodules in another three patients. Greater appreciation of the spectrum of the radiological abnormalities in CVID patients with interstitial lung disease is important. Deteriorating lung function in patients with granulomatous CVID may be secondary to interstitial lung disease rather than bronchiectasis, and treatment should be tailored accordingly.     

Acute- or Subacute-Onset Lung Complications in Treating Patients With Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a common systemic disease that manifests as inflammatory arthritis of multiple joints and produces a wide variety of intrathoracic lesions, including pleural diseases, diffuse interstitial pneumonia, rheumatoid nodules, and airway disease. Patients treated for RA can have associated lung disease that commonly manifests as diffuse interstitial pneumonia, drug-induced lung injury, and infection. The purpose of this pictorial review is to illustrate the radiographic and clinical features of lung complications of acute or subacute onset in patients treated for RA and to show the computed tomography features of these complications.     

The idiopathic interstitial pneumonias

This review includes the seven idiopathic interstitial pneumonias defined by The American Thoracic Society and The European Respiratory Society 2002 publication. Idiopathic pulmonary fibrosis is the clinical term for usual interstitial pneumonia. The radiologic pattern includes basal and subpleural ground glass and reticular opacities and honeycomb lung. Nonspecific interstitial pneumonia is characterized with a radiologic pattern of subpleural and basal ground glass and reticular opacities. Cryptogenic organizing pneumonia is manifest radiologically by peribronchial ground glass opacities and subpleural consolidation. Acute interstitial pneumonia is the clinical term for idiopathic diffuse alveolar damage and the exudative phase is characterized radiologically with diffuse ground glass opacification and dependent consolidation with the additional feature of lung architectural distortion in the organizing phase. Respiratory bronchiolitis associated interstitial lung disease manifests as centrilobular ground glass opacities on CT. Desquamative interstitial pneumonia is characterized by ground glass opacities with lower zone predominance on CT. Lymphoid interstitial pneumonia manifests by ground glass opacities and nodular interlobular septal thickening on CT. The diagnosis of an IIP should be rendered ideally only after all clinicoradiologic-pathologic data have been reviewed.     

Complications of pneumoconiosis: Radiologic overview

A wide spectrum of pulmonary complications occurs in patients with pneumoconiosis. Those complications include chronic obstructive pulmonary disease, hemoptysis, pneumothorax, pleural disease, tuberculosis, autoimmune disease, anthracofibrosis, chronic interstitial pneumonia, and malignancy. Generally, imaging workup starts with plain chest radiography. However, sometimes, plain radiography has limited role in the diagnosis of pulmonary complications of pneumoconiosis because of overlapping pneumoconiotic infiltration. Computed tomography (CT), ultrasonography (US), and magnetic resonance imaging (MRI) are potentially helpful for the detection of pulmonary complications in patients with pneumoconiosis. CT, with its excellent contrast resolution, is more sensitive and specific method than plain radiograph in the evaluation of pulmonary abnormalities. CT is useful in detecting lung parenchymal abnormalities caused by infection, anthracofibrosis, and chronic interstitial pneumonia. Also, CT is valuable in distinguishing localized pneumothorax from bullae and aiding the identification of multiloculated effusions. US can be used in detection of complicated pleural effusions and guidance of the thoracentesis procedure. MRI is useful for differentiating between progressive massive fibrosis and lung cancer.     

氨中毒的胸部X线表现

目的回顾性分析急性氨中毒致肺部损伤的X线表现。方法对37例急性氨中毒致肺部损伤病例的胸部X线表现进行分析,并进行1年随访观察。结果35例早期损伤表现为肺纹理增多,小叶性肺炎,间质性肺气肿,肺水肿等改变;15例晚期出现慢性支气管炎、肺间质纤维化及肺大泡等改变。结论急性氨中毒的肺部损伤是不可逆转的损伤。     

Pulmonary disorders and exercise

The respiratory system rarely limits exercise in the normal subject. In patients with chronic pulmonary processes or in the elite athlete, however, the respiratory system may indeed be the limiting factor. Common respiratory disorders include chest pain syndromes, cough, exercise-induced asthma, and vocal cord dysfunction. Chronic lung diseases such as asthma, COPD, and interstitial lung disease impact exercise capacity and endurance. Exercise testing can be useful to distinguish acute and chronic pulmonary causes of dyspnea during exercise, as well as to differentiate between cardiac and pulmonary causes.     

Subclinical interstitial lung involvement in rheumatic diseases. Correlation of high resolution computerized tomography and functional and cytologic findings]

INTRODUCTION: Rheumatic diseases are frequently associated with interstitial lung disease. Since interstitial fibrosis is an irreversible process, understanding the mechanisms leading to fibrosis is necessary for the development of treatment strategies to prevent irreversible pulmonary damage. High-resolution Computed Tomography (HRCT) is superior to chest radiography in assessing the presence and extent of parenchymal abnormalities in diffuse infiltrative lung diseases and provides a sensitive and noninvasive method of quantifying global disease extent. PURPOSE: The aims of this study were to quantify the severity and extent of subclinical interstitial lung disease as depicted on HRCT and to study the relationship between the patterns of lung disease quantified by HRCT and the functional parameters and bronchoalveolar lavage findings in patients with rheumatic diseases. PATIENTS: Eighty nonsmoking patients (24 patients with systemic sclerosis, 24 with primary Sj?gren's syndrome, 20 with rheumatoid arthritis and 7 with dermatopolymyositis) were examined. No patient had any signs or symptoms of pulmonary disease. RESULTS: Thirty-three of 80 patients (41.2%) had abnormal HRCT findings, namely isolated septal/subpleural lines, irregular pleural margins and ground-glass appearance. Chest X-ray showed parenchymal abnormalities in only 15 patients (18.7%) who had evidence of fibrosis on HRCT. Abnormal differential cell counts (alveolitis) at bronchoalveolar lavage were found in 46 of 80 patients (57.5%). Three types of alveolitis were observed: pure lymphocyte alveolitis, pure neutrophil alveolitis, and neutrophil alveolitis associated with lymphocytosis (mixed alveolitis). The patients with neutrophil alveolitis had more extensive disease on HRCT than those with lymphocyte alveolitis or with normal cellular patterns at bronchoalveolar lavage. The extent of a reticular pattern on HRCT correlated with the neutrophil rate (p = 0.001) and total count (p = 0.003) on bronchoalveolar lavage. Eosinophil and lymphocyte rate and total count correlated (p < 0.05) with the extent of the ground-glass pattern on HRCT. Lung volumes were not significantly different among patients with ground-glass pattern and those with reticular patterns on HRCT, while the diffusing capacity for carbon monoxide was significantly lower (p < 0.05) in the latter. CONCLUSIONS: HRCT is a sensitive tool in detecting interstitial lung disease in patients with rheumatic diseases with no signs and symptoms of pulmonary involvement. The relationship between the different HRCT patterns and bronchoalveolar lavage cell profiles can identify patients at higher risk of developing irreversible lung fibrosis. A long-term, prospective follow-up study is needed to determine whether these patients will develop over pulmonary disease.     

Collagen vascular disease-related lung disease: high-resolution computed tomography findings based on the pathologic classification

Collagen vascular disease (CVD) can cause a variety of lung abnormalities, including usual interstitial pneumonia, nonspecific interstitial pneumonia, organizing pneumonia, diffuse alveolar damage, lymphoid interstitial pneumonia, bronchiectasis, constrictive bronchiolitis, follicular bronchiolitis, alveolar hemorrhage, pulmonary hypertension, and drug-induced lung disease. The frequency of each lung disease is different among underlying CVDs. Although high-resolution computed tomography (HRCT) findings of lung disease are often nonspecific, there are some characteristic HRCT findings for some lung diseases based on pathologic findings.     

Smoking Related Interstitial Lung Disease - High Resolution Computed Tomography (HRCT) findings in 40 smokers

The aim of the study is to delineate the relation between cigarette smoking and the development of interstitial lung disease with declaration of the different types of the interstitial lung associated with smoking.