This appearance is virtually diagnostic, although under very rare circumstances both pulmonary papillomatosis and paragonimiasis may mimic cystic bronchiectases. 6.8 Varicella (chickenpox) pneumonia. Notice the dilated esophagus (e). 6.1c) consists of numerous punc-tate densities essentially ranging in diameter from 1 mm (barely visible as an individual lesion) to 5 mm, although a few slightly larger nodular lesions can be interspersed. Interstitial pulmonary fibrosis has many causes. There are two types of cystic patterns: thin-walled cysts (Fig. Figure 7-10 Interstitial nodules in sarcoidosis. Fig. Pneumoconiosis (inorganic dust) (e.g., silicosis, coal miner’s lung, berylliosis) (Figs. Some investigators have attempted to differentiate interstitial from airspace or acinar nodules on HRCT. Figure 7-11 Airspace nodules in bronchioloalveolar carcinoma. Interstitial lung disease is considered a misnomer by some, as many of the diseases also involve the alveolar spaces. Honeycombing is produced pathologically by the dissolution of alveolar walls with the formation of randomly distributed airspaces that are lined by fibrous tissue. 7-14) is a phenomenon that occurs in the presence of severe lung fibrosis and distortion of lung architecture, in which the fibrous tissue produces traction on the bronchial walls, resulting in irregular bronchial dilation. A subpleural line may be defined as a curvilinear opacity that is less than 1 cm from the pleural surface. A conundrum arises when widespread small opacities are difficult to categorize into one group or the other on chest radiography, or when ILD and ALD are both present. Numerous relatively poorly defined miliary nodules and bilateral hilar enlargement are present, but are only shown for the right side. Thin-walled cysts are seen in the lungs of a patient with lymphangioleiomyomatosis. 6.1e). Septal lines are a common feature of many interstitial lung disorders but are particularly predominant in lymphangitic spread of carcinoma and in congestive heart failure. 6.17). 6.18 Alveolar microlithiasis. Interstitial lung disease (ILD) is a negative prognostic factor associated with increased morbidity and mortality in patients with PM/DM (1-3). Clinical and radiologic correlation can aid the pathologist and refine the diagnosis. The reticular pattern consists of a network of linear densities (Fig. They include distribution of disease, pleural abnormalities, the size of the lungs, the presence of pulmonary arterial hypertension, and mediastinal and hilar adenopathy. Interstitial Lung Disease Jeffrey T. Chapman The term interstitial lung disease (ILD) refers to a broad category of lung diseases rather than a specific disease entity.1,2 It includes a variety of illnesses with diverse causes, treatments, and prognoses. In the more central portion of the lung, the thickened septa can outline the secondary pulmonary lobules, producing polygonal structures that are 1 to 2.5 cm in diameter. 6.1e). A nodular pattern (Fig. 6.17 Mitral stenosis (2 cases). Multiple small nodules are scattered throughout both lung fields. In t… The reticular pattern consists of a network of linear densities (Fig. Miliary and larger, poorly defined. Fig. This appearance is virtually diagnostic, although under very rare circumstances both pulmonary papillomatosis and paragonimiasis may mimic cystic bronchiectases. 7-3) and honeycombing. The characteristic com-puted tomographic findings in UIP are predominantly basal and pe-ripheral reticular opacities with honeycombing and traction bronchiec-tasis. In approximately 50% of cases, they are limited to one lung. ILDs may occur in isolation or in association with systemic diseases. Can result in nodular calcifications 1 to several years later. Fig. Bilateral small nodules with preferential involvement of the mid and lower lung zones are seen in this arc welder that are not associated with hilar adenopathy or fibrosis and resolved after exposure was discontinued. Fig. Large masses of fibrous tissue seen centrally in the upper lobes are associated with traction bronchiectasis (arrow). Extensive, predominantly cystic bronchiectases in the right lung and left lower lobe are associated with loss of volume in the affected lung and compensatory overinflation of the nonaffected left upper lobe. Thin-slices multi-detector computed tomography (MDCT) plays a key role in the differential diagnosis of interstitial lung disease (ILD). Some are primarily lung disorders, and some others are manifestations of diseases arising elsewhere. Miliary and larger (up to 3 cm). After completing this journal-based SA-CME activity, participants will be able to: 1. Webb and colleagues describe such HRCT findings in interstitial lung disease further in their work (see Suggested Readings). Fig. Box 7-3 Patterns of Opacities in Interstitial Lung Disease, Usual interstitial pneumonitis (idiopathic pulmonary fibrosis)*, Fibrosis associated with collagen vascular disease, Idiopathic pulmonary fibrosis (honeycombing), Congestive heart failure (interstitial edema). 7-11). Traction bronchiectasis (Fig. A ground-glass appearance (Fig. 17 Special Considerations for Asthma and Interstitial Lung Disease For additional ancillary materials related to this chapter, please visit thePoint. Kerley B lines are thinner and shorter than Kerley A lines (up to 2 cm) and lie in the lung periphery perpendicular to the lateral pleural surface (Fig. It usually involves the more central bronchi. Bronchiectases are often associated with loss of volume and crowding of the lung markings in the affected area together with compensatory overinflation of the spared lung (Fig. Bronchial wall thickening (white arrow) and small nodules are seen subpleurally along the fissures and lateral chest wall. 6.6 Histoplasmosis (2 cases). Publicationdate 2007-12-20. Miliary and larger, often indistinctly defined. 6.1b). Table 6.3 summarizes all disorders that demonstrate radiographically a diffuse reticular or reticulonodular pattern characteristic of interstitial lung disease. Lymphatic obstruction appears to be a major factor in the development of Kerley lines associated with malignancies (e.g., lymphangitic carcinomatosis, bronchogenic carcinoma, and lymphoma), since at least histologically, ipsilateral hilar involvement with tumor is almost invariably present under such conditions. Many diseases demonstrate more than one pattern (see, Patterns of Opacities in Interstitial Lung Disease, NODULAR OR RETICULAR NODULAR PATTERN (SMALL, ROUNDED OPACITIES), LINEAR PATTERN (SMALL, IRREGULAR, RETICULAR OPACITIES), PARENCHYMAL CONSOLIDATION (AIRSPACE OR ALVEOLAR DISEASE). The reticular pattern consists of a network of linear densities (Fig. The pathology is often inflammatory and always requires clinical and radiological context for a relevant and clinically useful histopathological diagnosis. The intralobular bronchiole often becomes visible when there is centrilobular thickening. Thick-walled cystic spaces can be seen subpleurally in the bases. Interpretation of lung biopsy specimens is an integral part in the diagnosis of interstitial lung disease. Development of high-resolution computed tomography (HRCT) has resulted in markedly improved accuracy in diagnosing interstitial lung disease. The following are the main technical components: 0.625- to 1.25-mm-thick sections, use of a high-resolution algorithm, targeted reconstruction to a single lung (optional), and prone scans to evaluate early or minimal basal disease. 6 Interstitial Lung Disease The chest radiograph, however, is often nonspecific. For example, histiocytosis, sarcoidosis, silicosis, and coal worker’s pneumoconiosis typically favor the upper lobes, whereas idiopathic pulmonary fibrosis and fibrosis associated with collagen vascular disease tend to be a lower-zone phenomenon. Varicella (chickenpox) pneumonia (Fig. The posteroanterior view shows coarse linear opacities distributed more in the lower lungs than upper areas. The ILD consist of disorders of known cause (e.g., collagen vascular diseases, drug-related diseases) as well as … Diseases have zonal preferences in the lungs (Box 7-4), although severe diseases often become diffuse. 7-2) frequently form a reticular pattern that may be fine or coarse. Fig. However, they can usually be differentiated from honeycombing by their larger and less uniform size and by the presence of tiny meniscus-like fluid levels at the bottom of these cystic lesions. 6.7). Localized fibrotic changes are often found in the chronic stage of a disease (e. g., tuberculosis and radiation pneumonitis). There are numerous interstitial lung diseases, but in clinical practice only about ten diseases account for approximately 90% of cases. Desquamative interstitial pneumonia and respiratory bronchiolitis-associated interstitial lung disease. Miliary and larger, usually poorly defined (acute stage). Prone scans are necessary to differentiate dependent atelectasis, a physiologic phenomenon that usually occurs posteriorly in the basal areas of the lungs, from true early interstitial lung disease. The term interstitial lung diseases (ILD) comprises a diverse group of diseases that lead to inflammation and fibrosis of the alveoli, distal airways, and septal interstitium of the lungs. 6.10 and 6.11). Honeycombing typically is in the peripheral portions of the lungs subpleurally, particularly in idiopathic pulmonary fibrosis. 6.1a). They are not truly acinar but may be considered airspace nodules (Fig. Bilateral miliary (a) and larger (b) scattered calcified nodules are present, but only shown for the right side. Most patterns can be readily identified on standard radiographs, but ground-glass and cystic disease patterns are much more readily appreciated on HRCT. It is found, besides in interstitial diseases, also with air-space disease (e.g. Gallium scanning and positron emission tomography (PET) have also been used in the evaluation of interstitial lung disease and are discussed in more detail in, A graphic or morphometric classification is a better approach and is enumerated in Box 7-3. Fig. Oily contrast material embolism (e.g., secondary to lymphography) (Fig. They have been called, Septal thickening in lymphangitic carcinomatosis. A central dot in the lobule is prominent, and the intralobular bronchiole is visible (arrowhead). Peripheral septal lines lie perpendicular to the pleural surface (open arrow). 6.2 Bronchiectases. 6.10 Silicosis. c Nodular pattern (silicosis). Thickening of the interlobular septa (Fig. Nonspecific interstitial pneumonia (NSIP): CT appearance. 7-1) is composed of multiple, small nodules that range from 1 mm to 1 cm in diameter. bronchiolitis–associated interstitial lung disease (RB-ILD); desquama-tive interstitial pneumonia (DIP); lymphoid interstitial pneumonia (LIP); and acute interstitial pneumonia (AIP). 6.1a). Cylindrical bronchiectases present as tubular opacities with parallel walls of 1 mm or slightly larger thickness. a Reticular pattern (Pneumocystis carinii pneumonia). Parenchymal consolidation (i.e., airspace or alveolar disease). 6.14 and 6.15). Hemosiderosis and pulmonary ossification secondary to mitral stenosis (Fig. 7-1) is composed of multiple, small nodules that range from 1 mm to 1 cm in diameter. Some are primarily lung disorders, and some others are manifestations of diseases arising elsewhere. This opacification obliterates the pulmonary vasculature. Multiple tiny nodules of high density are distributed evenly throughout both lungs, sparing only the apices. Bronchiectases are often associated with loss of volume and crowding of the lung markings in the affected area together with compensatory overinflation of the spared lung (Fig. If left untreated, the inflammatory process can progress to irreversible pulmonary … Patients invariably present with dyspnea of varying time course and severity. The process of evaluating a surgical lung biopsy for disease involves answering several questions. This appearance must be differentiated from a primary airway problem, bronchiectasis. Figure 7-4 Honeycombing pattern in the usual interstitial pneumonitis of scleroderma. Pattern recognition in diffuse interstitial lung disease has been the subject of controversy for many years. Honeycombing is the only dependable radiographic sign of interstitial fibrosis. More than 150 such disorders have been described, and a comprehensive list is provided in Box 7-1. Fig. Keywords Diffuse parenchymal lung disease, Interstitial lung disease, Lung disease, Lung transplantation, Parenchymal lung disease, Pulmonary Langerhans cell histiocytosis Key Points • For selected parenchymal lung disease (DPLD) patients who fail to respond to medical therapy and demonstrate declines in function that place them at increased risk for mortality, lung transplantation … Extensive, predominantly cystic bronchiectases in the right lung and left lower lobe are associated with loss of volume in the affected lung and compensatory overinflation of the nonaffected left upper lobe. Fig. Honeycombing pattern in the usual interstitial pneumonitis of scleroderma. A honeycomb pattern is characterized by round or oval cystic lesions with a diameter up to 1 cm (Fig. * More sensitive in detection of adenopathy than radiography. Physical examination frequently finds only dry rales or crackles. Miliary and slightly larger (up to 5 mm). Pattern that is predominant or usually associated with a specific disorder. The majority of interstitial lung diseases involve both lungs, or stated differently, the interstitial disease is usually diffuse, although some areas may be more affected and others more or less spared. 6.1d) is caused by a hazy increase in lung density that is not associated with obscuration of underlying vascular markings. 6.1c) consists of numerous punc-tate densities essentially ranging in diameter from 1 mm (barely visible as an individual lesion) to 5 mm, although a few slightly larger nodular lesions can be interspersed. Honeycomb spaces usually are 1 cm or less in diameter with relatively thick walls (>2 mm), and they are a pathologic correlate of end-stage lung disease with fibrosis (Fig. 6.1b). Many chronic diseases can produce diffuse opacities in the lung. Finely granular stippling uniformly distributed over both lung fields. These disorders are grouped together because of similarities in their clinical presentations, plain chest radiographic appearance, and…