key: cord-0036757-cy9zdg2j authors: Cagle, Philip T.; Roggli, Victor L. title: Pathology of Small Airways date: 2008 journal: Dail and Hammar’s Pulmonary Pathology DOI: 10.1007/978-0-387-68792-6_25 sha: 501e3a3bd720addfaf6859ad4f473660ab56bd56 doc_id: 36757 cord_uid: cy9zdg2j The small conducting airways consist of the membranous bronchioles and the respiratory bronchioles. Bronchiolitis is a generic term for inflammatory and fibrotic injuries of these small airways. The histology of normal bronchioles is discussed in detail in Chapter 2. A brief review is warranted here before discussing the histopathologic patterns associated with small airway injury. The small conducting airways consist of the membranous bronchioles and the respiratory bronchioles. Bronchiolitis is a generic term for inflammatory and fibrotic injuries of these small airways. The histology of normal bronchioles is discussed in detail in Chapter 2. A brief review is warranted here before discussing the histopathologic patterns associated with small airway injury. Bronchioles are defined as conducting airways less than 1 mm in diameter that lack cartilage in their walls. Bronchioles are divided into two groups: the larger (average 0.5 to 1 mm diameter) membranous bronchioles branch from the smallest bronchi and give rise to the smaller (average 0.15 to 0.2mm diameter) respiratory bronchioles. The final smallest division of the membranous bronchioles that branches into the first tier of respiratory bronchioles is often called the terminal bronchiole. The membranous bronchioles only conduct air similar to bronchi, whereas the respiratory bronchioles both conduct air and participate in gas exchange via the alveoli in their walls. The respiratory bronchioles branch into about two more generations of respiratory bronchioles with increasing numbers of alveoli in their walls and give rise to the alveolar ducts. 1.2 Terminal bronchioles are the most distal generation of bronchioles that do not contain alveoli. All membranous bronchioles have a simple columnar epithelium (bronchiolar mucosa) composed of ciliated columnar cells and nonciliated Clara cells, a layer of smooth muscle, and a connective tissue adventitia. Membranous bronchioles lack cartilage, and seromucinous glands and goblet cells are generally not observed or are minimal in the normal bronchiolar mucosa. The terminal membranous bronchiole leads into the acinus (a functional unit composed of the structures distal to a single terminal bronchiole-its respiratory bronchioles, alveolar ducts, and alveoli). A lobule is an anatomic unit consisting of the acini of three to 10 membranous bronchioles that are bounded together by the interlobular septa. As with 886 the bronchi, the bronchioles are accompanied by branches of the pulmonary artery of approximately the same diameter. 1 ,2 Respiratory bronchioles have a bronchiolar wall with simple columnar to cuboidal bronchiolar epithelium and alveoli budding from their walls. The alveoli budding from the bronchiolar walls increase in number the higher the generation of the respiratory bronchiole. In twodimensional longitudinal sections on glass slides, respiratory bronchioles often appear to have a bronchiolar mucosa and wall on one side of their lumen and alveolar spaces on the opposite side of their lumen. Respiratory bronchioles represent the first generation of airways in which exchange of gases occurs. 1.2 The histopathology of small airways may primarily involve the bronchioles alone or may be a component of a pulmonary disease characterized by other histopathologic changes. 3 -22 Focal small airways histopathology may be observed as a result of a localized acute injury such as a focal infection or bronchopneumonia. Further discussion of small airway injury as it relates to diseases and conditions involving the lungs can be found in other chapters, as follows: infections,23-35 Chapters 8 through 14; acute lung injury,6,7,9,10,22 Chapter 4; bronchial obstruction, including aspiration and asthma, 36 Several general histopathologic patterns are common to small airway injury regardless of etiology. Inflammation and fibrosis may involve the bronchiolar lumen, mucosa or wall, or the adjacent (peribronchiolar) tiers of alveolar septa. The bronchiolar epithelium or epithelium of peribronchiolar alveoli may also undergo metaplastic changes in association with inflammation and fibrosis, primarily with scarring as in constrictive bronchiolitis ( Fig. 25.1 ).104 These findings may be seen with both focal and diffuse airways injury. The basic patterns of small airway histopathology are listed in Table 25 .2. The types of metaplastic epithelium are listed in Table 25.3. Inflammation or scarring in bronchiolar walls or peribronchiolar tissue may result in decreased airflow that can often be measured physiologically as an obstructive change in the forced expiratory volume in 1 second (FEV1), and more specifically in forced expiratory flow after 25% to 75% of vital capacity has been expelled (FEF2s-7s) or forced expiratory flow after 75% of vital capacity has been expelled (FEF7s), However, small airways histopathologic changes may be associated with restrictive changes instead of or in addition to obstructive changes. The frequency with which bronchiolitis causes clinical symptoms is fairly uncommon compared to the frequency with which pathologists may encounter histopathologic lesions because of the large total cross-sectional area of the bronchioles. On the other hand, clinical symptoms may be severe despite what appears to be relatively mild small airway histopathology.los-l07 Bronchiolitis is recognized at low power as an inflammation or fibrosis that is centered in and around the bronchioles. In many cases of bronchiolitis, inflammatory infiltrates precede airway scarring, but this is not always the case and some lesions consist primarily or totally of scarring from the beginning of their course. Fibroblastic granulation tissue may precede mature scars. Findings of bronchiolitis may be nonspecific and it may be difficult to ascertain the underlying cause of either inflamed or scarred bronchioles. Additional nonspecific findings such as intra alveolar foamy macrophages due to small airway obstruction may be present, regardless of the etiology. Surface bronchiolar metaplasia of peribronchiolar fibrotic alveoli has been referred to as Lambertosis ( Fig. 25 .2). This term derives from an older concept that this metaplastic epithelium "grew out" from the adjacent bronchiole via the canals of Lambert. los PT. Cagle Organizing pneumonia or bronchiolitis obliterans with intraluminal polyps (formerly referred to as bronchiolitis obliterans-organizing pneumonia [BOOP]) is seen secondary to a variety of lung injuries and as a component of several specific lung diseases. The same histologic pattern occurs as an idiopathic clinical syndrome called cryptogenic organizing pneumonia (COP; formerly referred to as idiopathic BOOP), classified with the idiopathic interstitial pneumonias. 109-l36 Organizing pneumonia may occur in viral or other infections, as a drug reaction, as a reaction to chemotherapy or radiation therapy, after inhalation of fumes or toxic compounds, as a post obstructive finding distal to an obstructed airway, as a result of aspiration, and in bone marrow transplant recipients. It is proposed that this pattern may represent acute lung transplant rejection in some lung transplant patients. This pattern can also be a component of specific lung diseases including hypersensitivity pneumonitis, eosinophilic pneumonia, collagen vascular diseases involving the lungs, and Wegener's granulomatosis. 1,6.7.9, 10,17.19.22.109-136 The causes of organizing pneumonia are listed in Table 25 There may be accompanying interstitial lymphocytes or other inflammation. A trans bronchial biopsy may fail to sample bronchioles, and the only finding may be the granulation tissue in the alveoli. Intraalveolar collections of foamy macrophages may result from the bronchiolar obstruction. There may be findings that suggest Cryptogenic organizing pneumonia (COP), formerly termed idiopathic BOOP, consists of proliferation of granulation tissue within small airways, alveolar ducts, and alveoli, and is classified with the idiopathic interstitial pneumonias (Chapters 4 and 19). 137 The clinical syndrome occurs most often in middle-aged to older adults and is often preceded by a flu-like illness. Persistent nonproductive cough and shortness of breath are the usual presenting symptoms. Most, but not all, patients respond rapidly to steroids and in most cases prognosis is excellent. Typical radiologic features of cryptogenic organizing pneumonia are patchy bilateral alveolar infiltrates with a ground-glass appearance that sometimes may be transient and recurring in different locations. Diffuse interstitial infiltrates, focal consolidation, and small, rounded opacities are less frequently observed. On high-resolution computed tomography (HRCT), there are patchy bilateral areas of alveolar consolidation and ground-glass attenuation, often prominent in a peribronchial or subpleural distribution. 13 s--144 The histopathologic features are essentially the same as those of organizing pneumonia due to identifiable causes. At low power, COP consists of a patchy pattern of nodules of granulation tissue that typically center on a small airway surrounded by normal or near-normal lung ( Fig. 25 .6). At higher power there are arborizing branches of granulation tissue (fibroblasts in an edematous or myxoid stroma) that fill the lumina of bronchioles, alveolar ducts, and adjacent alveoli ( Fig. 25 .7). Rounded plugs of granulation tissue in the alveolar spaces are referred to as Masson bodies. The general architecture of FIGURE 25 .7. Granulation tissue branches through the lumina of small airways, alveolar ducts, and alveoli in cryptogenic orgalllzmg pneumonia. the lung is preserved, with no significant interstitial fibrosis or honeycombing. There may be small foci of lymphocytes, plasma cells, and macrophages in some bronchioles, and interstitial inflammation is usually minimal to moderate. Transbronchial biopsies may fail to sample bronchioles and sample only alveoli with organizing pneumonia. Intraalveolar collections of foamy macrophages may result from the bronchiolar obstruction. When an organizing pneumonia pattern is present, the pathologist should examine the tissue for viral inclusions, poorly formed granulomas, isolated giant cells (hypersensitivity pneumonitis), foreign-body giant cells (aspiration), and other entities.I.6,7,9. 10,17.19.22,109-137 Constrictive Bronchiolitis Constrictive bronchiolitis is a condition in which the bronchiolar lumina are severely narrowed or obliterated by submucosal scarring. Constrictive bronchiolitis is also called bronchiolitis obliterans and obliterative bronchiol- Table 25 .6. In constrictive bronchiolitis there is narrowing of the bronchiolar lumen by submucosal fibrous tissue or fibrous tissue in the adventitia or adjacent alveolar septa, which may display metaplastic epithelium or Lambertosis (Figs. 25.8 and 25.9). The narrowing may be subtle and the clinical symptoms and findings may be disproportionate to the histologic narrowing ( Fig. 25.10) . In other cases, some of the bronchiolar lumina may be completely obliterated leaving only a scarred remnant of the airway (Fig. 25.11 ). However, in contrast to COP, there is concentric constriction of the lumen without intraluminal granulation tissue plugs and, in contrast to granulation tissue plugs, the mature submucosal fibrosis does not potentially resolve and disappear. There may also be adventitialscarring and smooth muscle hypertrophy. Inftammation may be present or it may be minimal or absent. Trichrome Table 25 .7. Idiopathic constrictive bronchiolitis, in which patients lack any identifiable predisposing condition or exposure known to cause bronchiolitis, occurs primarily in nonsmoking middle-aged women. Patients present with a few months' history of cough and shortness of breath, often FIGURE 25.11 . Obliteration of a bronchiolar lumen by fibrosis leaves residual foci of bronchiolar epithelium in this example of constrictive bronchiolitis. Cellular bronchiolitis refers to bronchiolitis in which acute, chronic, or acute and chronic inflammatory infiltrates, or both types, are the primary histopathologic pattern.152.153 There is considerable overlap of the etiologies of these histopathologic patterns. Radiologic patterns vary and include the so-called tree-in-bud pattern. 15 4-156 Follicular bronchiolitis is a somewhat more distinct pattern associated with several different etiologies. 157 -170 More detailed discussions of the etiologies of these patterns of bronchiolitis can be found in the respective chapters dealing with these underlying conditions. For our purposes, this section serves as a brief overview of these relatively nonspecific patterns of cellular bronchiolitis, and the reader is referred to the respective chapters for more detailed discussion of the underlying conditions. Specific patterns of bronchiolitis are discussed in the next section. Etiology Acute bronchiolitis is typically an infectious respiratory disease in infants, as described in Chapters 7 and 11. The most common infectious agent in both children and adults is respiratory syncytial virus. 2 Acute bronchiolitis usually requires only symptomatic treatment, but patients, particularly infants, may sometimes require hospitalization. Patients present with tachypnea, wheezing, prolonged expiration, and tachycardia. Chest x-ray shows hyperinflation in most cases. 1.6,7,9,10.17,19,22 Radiographic findings are summarized in Table 25,9. Idiopathic cases are characterized by a chronic history (several years) of shortness of breath or cough, and an obstructive pattern on pulmonary function tests. Recurrent infections may be an associated finding,I,6,7,9,10,17,19.22 25 .12. Acute bronchiolitis shows filling of this bronchiolar lumen by purulent material and infiltration of the bronchiolar wall and mucosa by neutrophils. In acute bronchiolitis, there is filling of bronchiolar lumina by necropurulent exudates, and necrosis with sloughing of bronchiolar mucosa (Fig. 25.12 ). In acute and chronic bronchiolitis there is bronchiolar and peri bronchiolar infiltration by both acute and chronic inflammatory cells along with purulent exudates in the bronchiolar lumina ( Fig. 25.13 ). Occasional patients may have residual constrictive bronchiolitis. 1 ,6.7.9,10.17.19.22 FIGURE 25.13 . Acute and chronic bronchiolitis shows permeation of the bronchiolar mucosa and wall by both neutrophilic and lymphoplasmacytic infiltrates and filling of the lumen with purulent debris. In idiopathic cases, there are intraluminal purulent exudates and typically mural chronic inflammatory infiltrates, sometimes with follicular bronchiolitis. Bronchoalveolar lavage (BAL) specimens contain a large percentage of neutrophils.1.6,7,9.10,17.19,22 Most patients fully recover from acute bronchiolitis, although a few may have residual constrictive bronchiolitis as noted above. Fewer than 1 % of patients die as a result of acute bronchiolitis. Patients with idiopathic acute and chronic bronchiolitis may respond to antibiotics and may sometimes temporarily respond to immunosuppressive therapy. Most will have residual impairment of pulmonary function. 1,6,7.9. 10.17,19,22 Chronic Bronchiolitis Etiology Chronic bronchiolitis has overlapping etiologies with other patterns of cellular bronchiolitis. 1 . 6 ,7,9,10,17,19,22 Causes of chronic bronchiolitis are listed in Table 25 .10 and detailed discussions of these underlying conditions can be found in each of their respective chapters. Follicular bronchiolitis has some distinctive associations and is discussed separately. Clinical features include those of airway obstruction and radiographic features include small nodules on HRCT. Some forms of chronic bronchiolitis such as respiratory bronchiolitis are specific conditions discussed later. In chronic bronchiolitis, bronchiolar walls and peribronchiolar tissues are infiltrated by chronic inflammatory cells (Fig. 25.14) . Germinal centers may be present in the chronic inflammation in follicular bronchiolitis (discussed below). Changes of constrictive bronchiolitis may be 25 .14. Chronic bronchiolitis shows infiltration of bronchiolar mucosa and wall by chronic inflammatory cells. observed in some cases as the process progresses to airway scarring.1,6,7.9.10.17,19.22 Etiology Follicular bronchiolitis is lymphoid hyperplasia of the bronchus-associated lymphoid tissue (BALT) as a result of immune stimulus or altered immune response. Hence, follicular bronchiolitis may be seen in collagen vascular diseases, especially rheumatoid arthritis, immunodeficiency states, and lymphoproliferative disorders,157-170 Causes of follicular bronchiolitis are listed in Table 25 .11. With follicular bronchiolitis, most patients have progressive shortness of breath and may present with obstructive, restrictive, or mixed pulmonary functions,z2,157-170 Radiographic changes are bilateral and are listed in Table 25 .12. Etiology Granulomatous bronchiolitis may be due to any of several causes of granulomatous inflammation including infections. 171 The histopathology varies with the underlying disease. Well-formed granulomas with caseous necrosis in the walls of bronchioles are relatively classic for granulomatous infections; well-formed granulomas with no necrosis or only punctuate necrosis are suggestive of sarcoidosis; and poorly formed granulomas associated with interstitial infiltrates are typical of hypersensitivity pneumonitis (Fig. 25.16 ). Foreign material including squamous cells, vegetable matter, and skeletal muscle may be seen in association with aspiration (see Chapter 5).1,7, 19, 22 Prognosis Prognosis depends on the underlying etiology and its treatment. Prognosis for the underlying diseases is discussed in the respective chapters on each disease. Association with human leukocyte antigen (HLA)-Bw54 has been reported in Japan, leading to the proposal that HLA alleles or closely linked genes may contribute to a genetic predisposition to DPB. This might partly explain why this disorder is found primarily in Asians. [202] [203] [204] Patients typically have a history of chronic sinusitis, dyspnea on exertion, and cough. Over time, they develop purulent sputum production, obstructive pattern on pulmonary function tests, bilateral small nodular opacities on chest x-ray, and centrilobular lesions on HRCT. Highly elevated serum cold agglutinins are also typical. There is a slight male preponderance, and a wide age range with a mean of 50 years. Patients are commonly colonized with Haemophilus injiuenzae or Pseudomonas aeruginosa. Pseudomonas infection may develop and is associated with poor prognosis. Untreated cases of DPB typically progress to bronchiectasis and respiratory failure. Prolonged survival is frequently reported with chronic low-dose macrolide therapy. Although treatment of patients with macrolide antibiotics for infections began in 1983, Kudoh et aU 05 reported that chronic low-dose macrolide antibiotic therapy improved the course of DPB through mechanisms not related to treatment of infection. This is presumably as a result of nonspecific antiinflammatory effects of these antibiotics since they are effective even when Pseudomonas or other infections are not present. 20 6-2l1 Recurrence of DPB was reported by Baz et al. 212 in a patient who underwent lung transplantation. Grossly, in DPB, cut surfaces of the lungs demonstrate scattered 1-to 4-mm yellow nodules. There may also be gross findings of bronchiectasis or pneumonia (Fig. 25.17) . defining histopathologic feature of DPB and is defined as the involvement of the distal centrilobular conducting/ gas exchange unit.213 Membranous bronchioles may also be involved and may be ectatic. Follicular bronchiolitis, intraluminal acute inflammation, bronchiectasis, acute or organizing pneumonia, or postobstructive lipoid pneumonia may also be present. The conditions described in the following subsections, in which the lesions resemble those of DPB, have been reported in the literature: Relatively few patients with DPB have overt rheumatoid disease, although rheumatoid factor is often elevated, but a few authors have reported DPB lesions in patients with rheumatoid arthritisY4-218 Hayakawa et al. 216 used the term rheumatoid arthritis-associated bronchiolar disease (RA-BD) to refer to DPB-like lesions that differed from classic DPB in the following ways: (1) panbronchiolitis lesions were more common in DPB, (2) bronchiolar obliteration occurred at more proximal sites in RA-BD, (3) long-term macrolide therapy had less effect in RA-BD, and (4) HLA-B was more frequent in DPB (50% versus 22.2%). Pulmonary lesions resembling DPB have also been described in association with other collagen-vascular and autoimmune diseases including microscopic polyangiitis,219 Lambert-Eaton myasthenic syndrome and idiopathic thrombocytopenic purpura,220 ulcerative colitis, 221 Churg-Strauss syndrome,222 Sjogren's syndrome with malignant thymoma,223 and thymoma.224 Human T-Cell Lymphotropic Virus Type 1-Associated Bronchiolitis and Diffuse Pan bronchiolitis There are reports of clinical and histopathologic findings in patients with human T-cell lymphotropic virus type 1 (HTLV-1) that resemble DPB. [225] [226] [227] [228] In a study of 15 cases of HTLV-1-associated bronchiolitis and 43 cases of DPB, Kadota et al. 227 reported that HTLV-1-associated bronchiolitis had histopathologic features similar to DPB. However, a higher ratio of interleukin-2 receptor expression in T cells from BAL was found in HTLV-1-associated bronchiolitis and it did not respond as well to chronic macrolide therapy as DPB. Patients with adult T-cell leukemia 229 Table 25 .14.) Their 20 cases resembled DPB histopathologically, but using established criteria the cases could be differentiated from DPB. In general, foam cells were found in the walls of alveolar ducts and, to a lesser extent, in the walls of respiratory bronchioles. Cases of constrictive bronchiolitis, follicular bronchiolitis, bronchiectasis, and cystic fibrosis showed the greatest foam cell accumulation in membranous bronchioles or small bronchi, typically associated with lymphoid hyperplasia and scarring. Focal poorly developed PB-like lesions or occasional foci of interstitial foam cells associated with acute inflammation and intraluminal granulation tissue were observed in the other conditions. 233 reported a patient diagnosed with DPB 3 years previously who failed to respond to erythromycin. A diagnosis of eosinophilic bronchiolitis was made on a wedge biopsy. In 1985, a number of years before DPB was recognized as occurring in North America, the case of a 16-year-old girl undergoing lung transplant for bronchiolitis was reported as a case of xanthomatous bronchiolitis. 234 This young patient was not of Japanese or Asian descent and was from rural Texas. She did not have any of the conditions associated with PB-like lesions, and the dramatic accumulations of foam cells in her bronchioles were more severe than those seen secondary to other conditions. This case of xanthomatous bronchiolitis is probably best considered now as a variant of classic DPB. In addition to an absence of some of the expected clinical features, this case differs from classic DPB in that (1) the membranous bronchioles and small bronchi were more severely involved by foam cell infiltrates than expected in DPB, and (2) the quantity of both mural chronic inflammation and intraluminal acute inflammation are less than typically seen in most cases of DPB (Figs. 25.20, 25.21, and 25.22) . These differences may be related to the short course of the disease in a young patient, since most studied cases represent longstanding chronic disease in middle-aged to older adults or due to geo-ethnic differences. A number of mineral dusts can cause small airways fibrosis and obstruction. These are discussed in greater detail in Chapters 26 and 27. Etiology Tobacco smoke often causes inflammatory, sometimes fibrotic, lesions of the membranous bronchioles and Respiratory bronchiolitis is most often an incidental histopathologic finding involving occasional respiratory bronchioles and often also occasional membranous bronchioles in lung specimens from cigarette smokers. These lesions most often do not produce any clinically significant findings, although small airways obstruction may be detected by measurements of FEY], FEFz5-75, or FEF75. When clinically significant, small airway obstruction is often referred to as small airways disease. However, FEY], FEFz5_7S, and FEF75 do not distinguish clinically between obstruction of the proximal (membranous) and distal (respiratory) bronchioles. The severity of obstruction in patients with chronic obstructive pulmonary disease appears to correlate with the severity of bronchiolitis (see Chapter 24) . Less frequently, respiratory bronchiolitis may be more extensive and accompanied by clinical changes called respiratory bronchioli tis-associated in tersti tiall ung disease (RB ILD ), which is probably part of a spectrum from respiratory bronchiolitis to RBILD to desquamative interstitial pneumonia in terms of histopathologic extent and clinical severity. Patients with RBILD typically present with slow onset of cough and dyspnea and diffuse reticular to reticulonodular opacities on chest x-ray and ground-glass attenuation on HRCT. In desquamative interstitial pneumonia, there is involvement of greater volumes of lung tissue by collections of pigmented macrophages, and clinical findings are more severe (see Chapter 19 ) .1 ,6. 1, 9, 10, 17, 19, 22, 95, 147, Histopathologic Features Collections of lightly pigmented macrophages are found within the lumina of the bronchioles in respiratory bronchiolitis ( Fig. 25.23) . The finely granular particles within the macrophage cytoplasm are brown on hematoxylin and eosin (H&E), stain faintly with iron stain, and are known as smoker's pigment. The lumina of adjacent alveolar ducts and alveoli as well as membranous bronchioles typically contain collections of similarly pigmented macrophages (Fig. 25.24 ). The walls of the bronchioles also typically contain infiltrates of lymphocytes and histiocytes. The latter contain finely granular smoker's pigment or coarser black anthracotic pigment. Peri bronchiolar fibrosis may also be variably present in the bronchiolar walls and the first tiers of adjacent alveolar septa. The latter may also exhibit type II pneumocyte hyperplasia or metaplastic bronchiolar epithelium (Lambertosis ). In addition to the collections of pigmented macrophages, membranous bronchioles may exhibit murallymphocytic infiltrates,smooth muscle hyperplasia, adventitial fibrosis, and hyperplasia or metaplasia of the bronchiolar epithelium. Goblet cell metaplasia of the membranous bronchiolar epithelium and mucous plugs may be present. 235 -261 Histopathologic features of respiratory bronchiolitis and membranous bronchiolitis are listed in Table 25 .15. Cases of respiratory bronchiolitis even when associated with interstitial lung disease are usually self-limited and respond to cessation of smoking. 1, 6, 7, 9, 10, 17, 19, 22, 95, 147, Sauropus androgynus Ingestion Etiology Progressive difficulty breathing with obstructive ventilatory impairment following consumption of Sauropus androgynus262-278 was first reported in Taiwan in 1994 and 1995 with reports in the medical literature by Lin et a1. 262 and Lai et aU 63 in 1996. S. androgynus is a common vegetable food in Malaysia, and consumption of the raw leaf extract or its juice was a fad for losing weight. Most patients are young to middle-aged women who present within a few months of consumption of S. androgynus. Progressive dyspnea and persistent cough are the primary presenting symptoms. Patients have generally been reported to have obstructive ventilatory defects without bronchodilator response, with the severity sometimes reported as dose dependent. Lai et a1. 263 reported that chest x-rays were normal, but HRCT showed bilateral bronchiectasis and patchy low attenuation of lung parenchyma with mosaic pattern. Wu et a1. 267 . 273 and Kao et al. 274 reported that consumption of S. androgynus may result in either symptomatic or asymptomatic lung injury. They found that patients had obstructive or restrictive ventilatory impairment on pulmonary function tests and inhomogeneous radio-aerosol distribution as well as increased alveolar epithelial permeability on technetium-99m diethylenetriamine penta acetic acid (DTPA) lung scan. In the original report by Lin 25.25) . They also reported a predominance ofT cells by immunohistochemistry. The BAL fluid prior to treatment has been reported to have increased neutrophils and eosinophils. A study of four explanted lungs of patients receiving lung transplants,276 allowing for more extensive examination than biopsies, disclosed pathologic changes consistent with segmental ischemic necrosis of bronchi at the water-shed zone of bronchial and pulmonary circulation: fibromuscular sclerosis and obliteration P.T. Cagle and v.L. Roggli of bronchial arteries in the walls of large bronchi, segmental necrosis of small bronchi, fibrosis and atrophy of bronchial structures in immediately proximal bronchi, and obstruction and dilatation in immediately distal bronchi. They reported that most small bronchioles were " little altered." However, Wang et al. 278 subsequently reported a significant number of constrictive and obliterative bronchioles in one pneumonectomy and four biopsies. They also found fibromuscular intimal sclerosis of bronchial arteries in 15 % of bronchi 4 mm or less in diameter, which they proposed was only an indirect contributing factor. Patients with S. androgynus bronchiolitis obliterans develop progressive respiratory failure and do not respond to cessation of S. androgynus intake, large-dose steroids, bronchodilators, cytotoxic agents, or plasmapheresis. 273 . 275 Lung transplantation has been proposed as therapy for end-stage disease. 271 ,275.276,277 Bronchiolitis Due to Chemical Fumes Etiology Inhalation of a wide range of chemical fumes and smoke can cause small airways injury,279-308 An acute phase, an organizing phase, and a chronic phase of bronchiolar injury can be classically identified in many cases associated with inhalation of toxic fumes, although not all cases progress to a chronic phase, Fumes that can cause bronchiolitis are listed in Table 25 .16. During the acute phase immediately after fume exposure, the patient's symptoms depend on the type, amount, and circumstances of the exposure. 281 laryngospasm and bronchial spasm. With less severe exposures, patients may have cough, dyspnea, hypoxemia, cyanosis, and a variety of other symptoms such as headache, vomiting, and loss of consciousness. Most patients who survive the acute phase recover without long-term consequences. A small number progress to clinical illness over a period of a few weeks, with findings of obstructive disease and symptoms of cough, dyspnea, hypoxemia, and cyanosis. Bronchial wall thickening is commonly seen on the first chest x-ray subsequent to fume exposure. Later, bilateral consolidation may be seen. As noted, most cases resolve, but some cases progress to radiographic findings of constrictive bronchiolitis. 280.282,284,285,286,288,294-296,299,300,303-307 Histopathologically, in the acute phase there is acute inflammation and necrosis of the bronchiolar mucosa, which mayor may not be associated with adjacent findings of diffuse alveolar damage or pulmonary edema. The acute phase is followed by an organizing phase, in which the histopathologic features of organizing pneumonia (or bronchiolitis obliterans with intraluminal polyps, formerly referred to as BOOP) are found. The organizing phase resolves in the majority of cases, but some cases progress to constrictive bronchiolitis with narrowing or obliteration of bronchiolar lumina by scar. 295 ,296 Bronchiolitis Associated with Swyer-James Syndrome Swyer-James (Macleod) syndrome is unilateral radiographically hyperlucent lung associated with constrictive bronchiolitis and bronchiectasis, often as a result of childhood pulmonary infection. [309] [310] [311] [312] [313] [314] [315] [316] [317] [318] [319] [320] [321] [322] [323] [324] Etiology Most cases diagnosed as Swyer-James syndrome are rare complications of viral pneumonia and bronchiolitis in childhood, although other infections including Mycoplasma 311 and pertussis 323 are sometimes implicated, Patients typically develop bronchiectasis and recurrent infections including bacterial pneumonia, so that there are often multiple clinical and pathologic findings. Patients often have chronic cough and wheezing. Clinical and radiologic criteria for diagnosis of this syndrome include (1) unilateral loss of lung volume with hyperlucency on chest x-ray, (2) unilateral reduction in vascularity on computed tomography (CT) scan of the chest, and (3) unilateral loss of perfusion on technetium-99c lung scan.317 901 There are relatively few descriptions of the histopathology of Swyer-James syndrome?09,316,321-324 Histopathologic features that have been described include emphysema with widespread obliteration of the pulmonary capillary bed, bronchitis and bronchiolitis, peribronchial fibrosis and smooth muscle proliferation, bronchiectasis including cystic cavities lined by ciliated columnar epithelium, interstitial chronic inflammation and fibrosis, lymphoid nodules, and hypertrophy of the pulmonary artery. Marchevsky et a1. 324 recently described features from a pneumonectomy specimen including severe mixed centriacinar-panacinar emphysema in all lobes, bullous emphysema in the upper lobe, bronchiectases, mild interstitial pneumonia with fibrosis, and placental transmogrification of the pulmonary parenchyma of all three lobes, Most patients with Swyer-James syndrome are managed clinically, In one study of 13 patients with Swyer-James (MacLeod) syndrome, patients with saccular bronchiectasis had more frequent pneumonias than those without bronchiectasis or with cylindrical bronchiectasis. 3 Bronchiolar disorders Color atlas and text of pulmonary pathology Bronchiolitis obliterans: roentgenologic-pathologic correlation Adult bronchiolitis. Evaluation of bronchoalveolar lavage and response to prednisone therapy Diseases of the bronchioles The clinician's classification of the disease of the bronchioles Proliferative and constrictive bronchiolitis: classification and radiologic features Chest radiographic findings of the healthy and diseased bronchioles Diseases of the bronchioles Diseases of the bronchioles: CT and histopathologic findings CT mosaic pattern of lung attenuation: etiology and terminology Bronchiolitis: pathologic considerations Interstitial lung disease Small airway lesions HRCT of obliterative bronchiolitis and other small airways disease Obliterative bronchiolitis: varying presentations and clinicopathological correlation Bronchiolar disorders Bronchiolitis following infection in adults and children Post infectious bronchiolitis obliterans Pathogenesis of lower respiratory tract infections due to Chlamydia, Mycoplasma, Legionella and viruses Post-infectious bronchiolitis obliterans: clinical, radiological and pulmonary function sequelae Spectrum of manifestations of Swyer-james-MacLeod syndrome Respiratory syncytial virus-induced chemokine expression in the lower airways Respiratory syncytial virus and parainfluenza virus Bronchiolitis obliterans in the 1990s in Korea and the United States Bronchiolitis in infants Bronchiolitis: update The pathogenesis of respiratory syncytial virus disease in childhood Statin use is associated with improved function and survival of lung allografts CXCR2 regulates respiratory syncytial virus-induced airway hyperreactivity and mucus production Bronchiolitis in asthma and chronic obstructive pulmonary disease Bronchiectasis: functional significance of areas of decreased attenuation at expiratory CT Airway obstruction in asthmatic and healthy individuals: inspiratory and expiratory thin-section CT findings Importance of diffuse aspiration bronchiolitis caused by chronic occult aspiration in the elderly High-resolution CT features of severe asthma and bronchiolitis obliterans CT of airways disease and bronchiectasis Increased expression of the chemokine receptor CXCR3 and its ligand CXCLlO in peripheral airways of smokers with chronic obstructive pulmonary disease The role of small airways in lung disease Airway inflammation in severe chronic obstructive pulmonary disease: relationship with lung function and radiologic emphysema Progressive airway obliteration in adults and its association with rheumatoid disease Bronchiolitis and bronchitis in connective tissue disease: a possible relationship to the use of penicillamine Bronchiolitis and rheumatoid arthritis Airway involvement in ulcerative colitis Bronchiolitis in association with connective tissue disorders Airways involvement in rheumatoid arthritis The mechanism of respiratory failure in paraneoplastic pemphigus Clinical and radiological characteristics of lung disease in inflammatory bowel disease The interstitial pneumonias Small airways in idiopathic pulmonary fibrosis: comparison of morphologic and physiologic observations Idiopathic pulmonary fibrosis: current concepts Respiratory change in size of honeycombing: inspiratory and expiratory spiral volumetric CT analysis of 97 cases European Respiratory Society International Multidisciplinary Consensus Classification of the Idiopathic Interstitial Pneumonias High-resolution CT of idiopathic interstitial pneumonias Idiopathic bronchiolocentric interstitial pneumonia Airway-centered interstitial fibrosis: a distinct form of aggressive diffuse lung disease Factors contributing to mortality in lung transplant recipients: an autopsy study Efficacy of trans bronchial lung biopsy in the diagnosis of bronchiolitis obliterans in heart-lung transplant recipients Lymphocyte subset populations in bronchiolitis obliterans after heart-lung transplantation A working formulation for the standardization of nomenclature and for clinical staging of chronic dysfunction in lung allografts Bronchiolitis associated with bone marrow transplantation Airway obstruction and bronchiolitis obliterans after lung transplantation Diagnosis of chronic lung transplant rejection by transbronchial biopsy Bronchiolitis obliterans in recipients of single, double and heart-lung transplantation A revision of the 1990 working formulation for the classification of lung allograft rejection Lung transplantation Bronchiolitis obliterans after human lung transplantation Bronchiolitis obliterans syndrome 2001: an update of the diagnostic criteria The pulmonary pathology of farmer's lung disease Airflow obstruction and airway lesions in hypersensitivity pneumonitis Inhalational lung injury causing bronchiolitis Hypersensitivity pneumonitis: correlation of individual CT patterns with functional abnormalities Bronchiolitis in chronic pigeon breeder's disease: morphologic evidence of a spectrum of small airway lesions in hypersensitivity pneumonitis induced by avian antigens Airway involvement in hypersensitivity pneumonitis Reed CEo Hypersensitivity pneumonitis: current concepts and future questions Chronic eosinophilic pneumonia Constrictive bronchiolitis obliterans following gold therapy for psoriatic arthritis Bronchiolitis obliterans in a patient with localized scleroderma treated with D-penicillamine Pulmonary drug toxicity: radiologic and pathologic manifestations Drug-induced lung injury Interstitial lung disease induced by drugs and radiation Bronchiolitis obliterans organizing pneumonia associated with sulfasalazine in a patient with rheumatoid arthritis Pathologic characteristics of druginduced lung disease Small airways disease and mineral dust exposure: prevalence, structure, and function Radiographic type p pneumoconiosis: thin-section CT Mineral dust induced bronchiolitis Bronchiolitis obliterans from exposure to incinerator fly ash Respiratory health effects of carbon black: a survey of European carbon black workers Pathology of occupational lung disease Pathology of asbestos-associated diseases Pulmonary Langerhans' -cell histiocytosis Soler P Three-dimensional characterization of pathologic lesions in pulmonary Langerhans cell histiocytosis Pulmonary Langerhans cell histiocytosis: what was the question? Pulmonary sarcoidosis: morphologic associations of airflow obstruction at thin-section CT Air trapping in sarcoidosis on computed tomography: correlation with lung function Idiopathic diffuse hyperplasia of pulmonary neuroendocrine cells and airways disease Neuroendocrine cell hyperplasia and obliterative bronchiolitis in patients with peripheral carcinoid tumors Obliterative bronchiolitis caused by multiple tumourlets and microcarcinoids successfully treated by single lung transplantation Bronchiolitis obliterans due to neuroendocrine hyperplasia: high resolution CTpathologic correlation Bronchiolar and peri bronchiolar inflammation, fibrosis and metaplasia Site and nature of airway obstruction in chronic obstructive lung disease Smoking, airflow limitation and the pulmonary circulation A normal FEV1IVC ratio does not exclude airway obstruction Pulmonary histology for the surgical pathologist Cryptogenic obliterative bronchiolitis in adults Cryptogenic organizing pneumonitis Bronchiolitis obliterans organizing pneumonia Radiographic manifestation of bronchiolitis obliterans with organizing pneumonia vs usual interstitial pneumonia Bronchiolitis obliterans and usual interstitial pneumonia: a comparative clinicopathologic study Differential diagnosis of bronchiolitis obliterans with organizing pneumonia and usual interstitial pneumonia: clinical, functional, and radiographic findings Bronchiolitis obliterans organizing pneumonia: CT features in 14 patients Bronchiolitis obliterans organizing pneumonia: a British view Bronchiolitis obliterans organizing pneumonia: definition and clinical features Cryptogenic organizing pneumonia: the North American experience Imaging of small airways diseases Rapidly progressive bronchiolitis obliterans with organizing pneumonia Cryptogenic organizing pneumonia: CT findings in 43 patients Solitary lung lesions in Wegener's granulomatosis. Pathologic findings and clinical significance in 25 cases Bronchiolitis obliterans-organizing pneumonia (BOOP)-like variant of Wegener's granulomatosis. A clinicopathologic study of 16 cases Organizing pneumonia: features and prognosis of cryptogenic, secondary, and focal variants Cyclophosphamide in severe steroid-resistant bronchiolitis obliterans organizing pneumonia Idiopathic bronchiolitis obliterans organizing pneumonia/cryptogenic organizing pneumonia with unfavorable outcome: pathologic predictors Organising pneumonia Cryptogenic organizing pneumonia: characteristics of relapses in a series of 48 patients Cryptogenic organizing pneumonia Update on cryptogenic organising pneumonia (idiopathic bronchiolitis obliterans organising pneumonia) Cytokine profile of broncho-alveolar lavage in BOOP and UIP Sarcoidosis Vasc Diffuse Lung Paakko P VEGF and bFGF are highly expressed in intraluminal fibromyxoid lesions in bronchiolitis obliterans organizing pneumonia Organizing pneumonia: the many morphological faces Bronchiolitis obliterans. Organizing pneumonia Cryptogenic organizing pneumonia Pulmonary pathological features in corona virus associated severe acute respiratory syndrome (SARS) Classification of idiopathic interstitial pneumonias: making sense of the alphabet soup Carrington CB. Bronchiolitis obliterans Small airways disease: expiratory computed tomography comes of age Bronchiolar inflammatory diseases: high-resolution CT findings with histologic correlation Imaging of the chest: idiopathic interstitial pneumonia Imaging of unusual diffuse lung diseases The idiopathic interstitial pneumonias Diseases affecting the peribronchovascular interstitium: CT findings and pathologic correlation Bronchiolitis obliterans-current concepts Constrictive (obliterative) bronchiolitis: diagnosis, etiology, and a critical review of the literature Clinical spectrum of adult chronic bronchiolitis The radiology of cryptogenic obliterative bronchiolitis Cryptogenic constrictive bronchiolitis: a clinicopathologic study Cryptogenic constrictive bronchiolitis imitating imaging features of diffuse panbronchiolitis A case of idiopathic constrictive bronchiolitis in a middle-aged male smoker Bronchiolitis, an update Sao Paulo BO Study Group. Lymphocytic inflammation in childhood bronchiolitis obliterans CT patterns of bronchiolar disease: what is "tree-in-bud"? The tree-in-bud sign The radiological spectrum of small-airway diseases Follicular bronchiolitis in association with connective tissue diseases Follicular bronchitis/bronchiolitis Surgical pathology of the lung in Wegener's granulomatosis. Review of 87 open lung biopsies from 67 patients Follicular bronchiolitis associated with rheumatoid arthritis Follicular bronchitis in the pediatric population Pulmonary lymphoid disorders Middle lobe syndrome: a clinicopathological study of 21 patients Bronchiolar disease in rheumatoid arthritis Chid a K. Cellular distribution of bronchus-associated lymphoid tissue in rheumatoid arthritis Follicular bronchiolitis: thin-section CT and histologic findings Follicular hyperplasia of bronchus-associated lymphoid tissue causing severe air trapping Clinical and histopathological findings in two Turkish children with follicular bronchiolitis Follicular bronchiolitis (FBB) associated with Legionella pneumophila infection Follicular bronchiolitis associated with Legionella pneumophila infection Bronchiolitis in rheumatoid arthritis Treated Wegener's granulomatosis: distinctive pathological findings in the lungs of 20 patients and what they tell us about the natural history of the disease The histological spectrum of chronic necrotizing forms of pulmonary aspergillosis Pathologic findings in lung volume reduction surgery Granulomatous bronchiolitis associated with Crohn's disease Obstructive granulomatous bronchiolitis due to Mycobacterium avium complex in an immunocompetent man Three-dimensional characterization of pathologic lesions in pulmonary Langerhans cell histiocytosis Pathology of allergic bronchopulmonary aspergillosis Noninfectious lung pathology in patients with Crohn's disease Lawson E1 Granulomatous bronchiolitis with necrobiotic pulmonary nodules in Crohn's disease Diffuse panbronchiolitis Report of three cases and review of the literature The first report of diffuse panbronchiolitis in Korea: five case reports Diffuse pan bronchiolitis observed in an Italian male Smith G1 Diffuse panbronchiolitis in a Hispanic man with travel history to Japan Diffuse panbronchiolitis in an Asian immigrant Diffuse panbronchiolitis in the United States A report of the first three cases of diffuse panbronchiolitis in Malaysia Diffuse panbronchiolitis: histologic diagnosis in unsuspected cases involving North American residents of Asian descent Diffuse panbronchiolitis: case report and review of the literature Clinical profiles of Chinese patients with diffuse panbronchiolitis Diffuse panbronchiolitis, the first case reports in Thailand Diffuse panbronchiolitis observed in a white man in Turkey Diffuse pan bronchiolitis in Latin America Diffuse panbronchiolitis-a case report Diffuse panbronchiolitis: a treatable sinobronchial disease in need of recognition in the United States Diffuse panbronchiolitis: an underdiagnosed disease? Study of 4 cases in Brazil Diffuse panbronchiolitis in a Caucasian man in Canada Zhu Y1 Diffuse panbronchiolitis with histopathological confirmation among Chinese Problems in chronic obstructive bronchial diseases, with special reference to diffuse panbronchiolitis Diffuse panbronchiolitis. A disease of the transitional zone of the lung Association of HLA class I antigens with diffuse pan bronchiolitis in Korean patients Fine localization of a major disease-susceptibility locus for diffuse panbronchiolitis Identification of novel candidate genes in the diffuse panbronchiolitis critical region of the class I human MHC Clinical effects of low-dose long-term erythromycin chemotherapy on diffuse pan bronchiolitis Diffuse panbronchiolitis: efficacy of low-dose erythromycin Kadota Ji 1. Non-antibiotic effect of antibiotics Macrolide antibiotics and pulmonary inflammation Diffuse panbronchiolitis: role of macrolides in therapy Long-term efficacy and safety of clarithromycin treatment in patients with diffuse pan bronchiolitis Macrolide activities beyond their antimicrobial effects: macrolides in diffuse pan bronchiolitis and cystic fibrosis Recurrence of diffuse pan bronchiolitis after lung transplantation Diffuse panbronchiolitis: diagnosis and distinction from various pulmonary diseases with centrilobular interstitial foam cell accumulations Diffuse panbronchiolitis and rheumatoid arthritis: a possible correlation with HLA-B54 An autopsy case of diffuse panbronchiolitis accompanying rheumatoid arthritis Diffuse panbronchiolitis and rheumatoid arthritis-associated bronchiolar disease: similarities and differences Diffuse panbronchiolitis in rheumatoid arthritis Rheumatoid arthritis associated with diffuse panbronchiolitis Microscopic polyangiitis associated with diffuse panbronchiolitis Lambert-Eaton myasthenic syndrome associated with idiopathic thrombocytopenic purpura and diffuse panbronchiolitis: long-term remission after a course of intravenous immunoglobulin 907 combined with low-dose prednisolone Diffuse panbronchiolitis preceding ulcerative colitis Allergic granulomatosis and angiitis (Churg-Strauss syndrome) A case of diffuse panbronchiolitis complicated by malignant thymoma and Sjogren's syndrome Diffuse pan bronchiolitis complicated with thymoma: a report of 2 cases with literature review Human T-cell Iymphotropic virus type I (HTLV-I) carrier with clinical manifestations characteristic of diffuse panbronchiolitis Detection of human T Iymphotropic virus type I proviral DNA in patients with diffuse panbronchiolitis Clinical similarities and differences between human T-cell Iymphotropic virus type I-associated bronchiolitis and diffuse panbronchiolitis A case of diffuse panbronchiolitis (DPB) in a patient positive for HTLV-l Diffuse panbronchiolitis as a pulmonary complication in patients with adult T-cell leukemia Non-Hodgkin lymphoma associated with diffuse panbronchiolitis Cryptogenic constrictive bronchiolitis imitating imaging features of diffuse pan bronchiolitis Idiopathic bronchiolitis mimicking diffuse panbronchiolitis Chronic bronchiolitis with associated eosinophilic lung disease (eosinophilic bronchiolitis) Xanthomatous bronchiolitis obliterans with cholesterol pneumonia Pathologic changes in the peripheral airways of young cigarette smokers Natural history and treated course of usual and desquamative interstitial pneumonia Respiratory bronchiolitis causing interstitial lung disease: a clinicopathologic study of six cases Respiratory bronchiolitis-associated interstitial lung disease and its relationship to desquamative interstitial pneumonia High resolution CT in respiratory bronchiolitis associated interstitial lung disease Respiratory bronchiolitis-associated interstitiallung disease Morphologic aspects of cigarette smoking on airways and pulmonary parenchyma in healthy adult volunteers: CT evaluation and correlation with pulmonary function tests Disease progression in usual interstitial pneumonia compared with desquamative interstitial pneumonia: assessment with serial CT Cigarette smoking: CT and pathologic findings of associated pulmonary diseases Cordier JE Respiratory bronchiolitis in smokers with spontaneous pneumothorax Idiopathic pulmonary fibrosis: clinical relevance of pathologic classification Respiratory bronchiolitis, respiratory bronchiolitis-associated interstitial lung disease, and desquamative interstitial pneumonia: different entities or part of the spectrum of the same disease process? Clinical significance of respiratory bronchiolitis on open lung biopsy and its relationship to smoking related interstitial lung disease The pathology of smokingrelated lung diseases Smoking-related interstitial lung diseases Respiratory bronchiolitis associated with severe dyspnea, exertional hypoxemia, and clubbing Desquamative interstitial pneumonia and respiratory bronchiolitis-associated interstitial lung disease Smokingrelated interstitial lung diseases: concise review Respiratory bronchiolitis: a clinicopathologic study in current P.T. Cagle and v.L. Roggli smokers, ex-smokers, and never-smokers Respiratory bronchiolitis-associated interstitial lung disease: radiologic features with clinical and pathologic correlation Smoking-related interstitiallung diseases: histopathological and imaging perspectives The overlap between respiratory bronchiolitis and desquamative interstitial pneumonia in pulmonary Langerhans cell histiocytosis: high-resolution CT, histologic, and functional correlations Respiratory bronchiolitis associated with interstitial lung disease Desquamative interstitial pneumonia, respiratory bronchiolitis and their relationship to smoking Respiratory bronchiolitis associated with interstitial lung disease and desquamative interstitial pneumonia Cigarette smoking in interstitial lung disease: concepts for the internist Desquamative interstitial pneumonia and respiratory bronchiolitis-associated interstitial lung disease Deng JE Outbreak of obstructive ventilatory impairment associated with consumption of Sauropus androgynus vegetable Outbreak of bronchiolitis obliterans associated with consumption of Sauropus androgynus in Taiwan Increased IL-5 and IL-lO transcription in bronchial cells after Sauropus androgynus ingestion Histopathological study of Sauropus androgynus-associated constrictive bronchiolitis obliterans: a new cause of constrictive bronchiolitis obliterans Tseng CI Association of Sauropus androgynus and bronchiolitis obliterans syndrome: a hospital-based case-control study Lung injury related to consuming Sauropus androgynus vegetable Correlation of highresolution CT and pulmonary function in bronchiolitis obliterans: a study based on 24 patients associated with consumption of Sauropus androgynus Segmental necrosis of small bronchi after prolonged intakes of Sauropus androgynus in Taiwan Dose-response relationship and irreversible obstructive ventilatory defect in patients with consumption of Sauropus androgynus Lung transplantation in Sauropus androgynus consumption patients in Taiwan Computed tomographic imaging of bronchiolar disorders The effect of large-dose prednisolone on patients with obstructive lung disease associated with consuming Sauropus androgynus Using 99mTc-DTPA radioaerosol inhalation lung scintigraphies to detect the lung injury induced by consuming Sauropus androgynus vegetable and comparison with conventional pulmonary function tests Lung transplantation for patients with end-stage Sauropus androgynus-induced bronchiolitis obliterans (SABO) syndrome Retransplantation of contralateral lung in a patient with Sauropus androgynus-induced bronchobronchiolitis obliterans Intermediate results in Sauropus androgynus bronchiolitis obliterans patients after singlelung transplantation Sauropus androgynus-constrictive obliterative bronchitis/bronchiolitis-histopathological study of pneumonectomy and biopsy specimens with emphasis on the inflammatory process and disease progression Bronchiolitis from nitrous fumes Nitrogen dioxide inhalation and bronchiolitis obliterans. A review of the literature and report of a case Acute bronchiolitis following provocative inhalation of "alcalase"-a proteolytic enzyme used in the detergent industry Bronchiolitis obliterans and tracheal stenosis. Late complications of inhalation burn Fatal anhydrous ammonia inhalation Severe obstructive lung disease after smoke inhalation Obstructive lung disease from acute sulfur dioxide exposure Bronchiolitis obliterans from a burning automobile Fatal ammonia inhalation. A case report with autopsy findings Report of three cases with detailed physiologic studies Zinc chloride (smoke bomb) inhalationallung injury Disaster at Bhopal: the accident, early findings and respiratory health outlook in those injured Lithium battery hazard: old-fashioned planning implications of new technology Chemical pneumonitis due to exposure to bromine compounds The plain chest radiograph after acute smoke inhalation Thionyl-chloride-induced lung injury and bronchiolitis obliterans Inhalational lung injury causing bronchiolitis Fume-related bronchiolitis obliterans Acute inhalation injury Toxic gas inhalation Bronchiolitis obliterans in a man who used his wood-burning stove to burn synthetic construction materials Persistent respiratory effects in survivors of the Bhopal disaster Review article: acute inorganic mercury vapor inhalation poisoning Occupational airway diseases Clinical bronchiolitis obliterans in workers at a microwave-popcorn plant Bronchiolitis obliterans in a survivor of a chemical weapons attack Chronic bronchiolitis in a 5-yr-old child after exposure to sulphur mustard gas Long-term respiratory disorders of claimers with subclinical exposure to chemical warfare agents Aslani 1. Bronchiolitis obliterans following exposure to sulfur mustard: chest high resolution computed tomography Acute inhalation injury with evidence of diffuse bronchiolitis following chlorine gas exposure at a swimming pool A case of unilateral pulmonary emphysema Abnormal transradiancy of one lung Unilateral hyperlucent lung (Swyer-James syndrome) after severe Mycoplasma pneumoniae infection Hyperlucent lung: long-term complication of adenovirus type 7 pneumonia Swyer-James syndrome-unilateral hyperlucent lung syndrome. A case report and review Obliterative bronchiolitis in children CT findings in Swyer-James syndrome A case of surgical treatment of Swyer-James syndrome Spectrum of manifestations of Swyer-James-MacLeod syndrome Swyer-James-MacLeod syndrome Macleod's syndrome presenting with spontaneous pneumothorax Bronchiolitis obliterans in children: clinical profile and diagnosis Surgically treated Swyer-James syndrome Clinical, physiologic, and roentgenographic changes after pneumonectomy in a boy with Macleod/Swyer-James syndrome and bronchiectasis MacLeod's) syndrome following pertussis infection in an infant MacLeod) syndrome with placental transmogrification of the lung: a case report and review of the literature