How to identify interstitial pneumonias.

Transcription

1 How to identify interstitial pneumonias. Poster No.: C-0804 Congress: ECR 2014 Type: Educational Exhibit Authors: S. claret loaiza, M. C. Cañete Moslero, R. Carreño Gonzalez, C. de la Torre; Malaga/ES Keywords: Thorax, CT-High Resolution, Diagnostic procedure, Image verification DOI: /ecr2014/C-0804 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 38

2 Learning objectives To describe the radiological findings of interstitial pneumonias and correlate them with the epidemiological data, clinical manifestations and histopathological patterns in order to make an accurate diagnosis. Background Interstitial lung diseases refer to a group of lung diseases affecting the interstitium (the tissue and space around the air sacs of the lungs). It concerns alveolar epithelium, pulmonary capillary endothelium, basement membrane, perivascular and perilymphatic tissues. When we suspect interstitial lung disease is critical to know if it is idiopathic because interstitial pneumonias with known cause (connective tissue diseases, hipersensitivity pneumonitis, etc.) have a different treatment and prognosis (Fig. 1) Page 2 of 38

3 Fig. 1: The alveoli and the secondary pulmonary lobule. References: - Malaga/ES The idiopathic interstitial pneumonias (IIPs) are a subset of diffuse interstitial lung diseases of unknown etiology characterized by a non-specific clinical and laboratory findings, what make them a "diagnosis of exclusion". IIPs include seven entities: idiopathic pulmonary fibrosis, which is characterized by the morphologic pattern of usual interstitial pneumonia (UIP); desquamative interstitial pneumonia (DIP); respiratory bronchiolitis-associated interstitial lung disease (RB-ILD); acute interstitial pneumonia (AIP); lymphoid interstitial pneumonia (LIP); nonspecific interstitial pneumonia (NSIP) and cryptogenic organizing pneumonia (COP). The most representative cases of IIP occurred in our hospital during the period 1 Sept/12-1 Sept/13 are shown. A revision of the clinical history and the histopathological findings was made in each case. Page 3 of 38

4 Images for this section: Fig. 1: The alveoli and the secondary pulmonary lobule. Page 4 of 38

5 Findings and procedure details Idiopathic Pulmonary Fibrosis (Fig. 2) Fig. 2: Summary of Idiopathic Pulmonary Fibrosis. References: - Malaga/ES Epidemiological and clinical data - It is the most common disease, about 50-60% of all idiopathic interstitial pneumonias, with a higher prevalence in men, usually over 50 years. Patients usually present with progressive shortness of breath and nonproductive cough. Pathology - The histologic diagnosis is based on temporal heterogeneity: the identification of fibrotic lesions of different stages (fibroblastic foci, mature fibrosis and honeycombing) within the same biopsy specimen. In addition to the temporal heterogeneity, the histologic abnormality is spatially heterogeneous, with patchy lung involvement and normal lung adjacent to severely fibrotic lung. Page 5 of 38

6 CT findings (Fig. 3) - Consist in a radiological pattern of usual interstitial pneumonia (UIP), characterized on the presence of reticular opacities, often associated with traction bronchiectasis. Honeycombing is common. Ground-glass opacity is common but is usually less extensive than the reticular pattern. Architectural distortion, which reflects lung fibrosis, is often prominent. The distribution of UIP on CT images is characteristically basal and peripheral, though it is often patchy. With the progression of the disease, appears a subpleural reticular abnormalities in upper lobes wich, associated with honeycombing, are an important hallmark of the NIU. Fig. 3: IPF in a 68-year-old man with mild dyspnea. Axial CT images show honeycombing (orange area), reticular pattern (blue area) and traction bronchiectasis (yellow area). References: - Malaga/ES When ground-glass pattern is extensive, we should to think in NID or NINE before NIU. If pulmonary fibrosis is known, consider the possibility of an acute exacerbation or accelerated deterioration of the disease. Complications and prognosis - Important complications of idiopathic pulmonary fibrosis include infection, lung cancer, and accelerated deterioration. Since most treatments for idiopathic pulmonary fibrosis cause immunocompromise, a variety of opportunistic infectious organisms may be present in these patients, including Pneumocystis carinii, Mycobacterium avium-intracellulare complex, and mycetoma due to Aspergillus species or other organisms. The reported frequency of lung cancer is about 10%-15%. When cancer occurs, it seems to predominantly affect the lower lobes. Accelerated deterioration ("acute exacerbation") of idiopathic pulmonary fibrosis manifests with a relatively short onset of progressive dyspnea or cough, occasionally associated with systemic symptoms, in a patient with underlying idiopathic pulmonary fibrosis. On CT images, the accelerated deterioration is characterized by diffuse or peripheral groundglass opacification, which must be distinguished clinically from opportunistic viral or Pneumocystis infection. Page 6 of 38

7 The median survival from time of diagnosis varies between 2.5 and 3.5 years. Idiopathic pulmonary fibrosis, as currently defined, does not usually respond to steroid treatment, in contrast to the other IIPs. Desquamative Interstitial Pneumonia (Fig. 4) Fig. 4: Summary of Desquamative Interstitial Pneumonia References: - Malaga/ES Epidemiological and clinical data - It is an uncommon condition that primarily affects cigarette smokers in their 4th or 5th decades of life. DIP is more common in men than in women (male-to-female ratio, 2:1). A progressive onset of dyspnea and dry cough is usual, and patients may progress to respiratory failure. Pathology - It is characterized by spatially homogeneous thickening of alveolar septa, associated with intraalveolar accumulation of macrophages. The term desquamative was Page 7 of 38

8 applied to this entity because the intraalveolar macrophages were initially thought to represent desquamated alveolar cells. CT findings(fig. 5) - Ground-glass opacification, present on CT images in all cases of DIP, is due to the spatially homogeneous accumulation of intraalveolar macrophages and alveolar septal thickening. The abnormality has a lower-zone and peripheral distribution in the majority of cases. Irregular linear opacities and a reticular pattern are frequent but are limited in extent and are usually confined to the lung bases. Honeycombing is uncommon, but well-defined cysts may occur within the areas of ground-glass opacification. Can be observed traction bronchiectasis. It is common a centrilobular emphysema, predominantly in higher fields. Fig. 5: DIP in a 57-year-old man. Axial and coronal CT images of the lower lung lobes shows extensive bilateral ground-glass opacities (green area). References: - Malaga/ES Respiratory Bronchiolitis-associated Interstitial Lung Disease (Fig. 6) Page 8 of 38

9 Fig. 6: Summary of Respiratory Bronchiolitis-associated Interstitial Lung Disease. References: - Malaga/ES Epidemiological and clinical data - It usually affects current smokers years of age with a 30 pack-year or greater history of cigarette smoking. There is a slight male predominance. Mild cough and dyspnea are the most common presenting symptoms. Pathology - It is characterized by pigmented macrophages and mild interstitial inflammatory changes centering on respiratory bronchioles and neighboring alveoli. The alveolar septa in the peribronchial regions may be mildly thickened but without significant fibrosis. CT findings (Fig. 7) - The most common high-resolution CT findings in RB-ILD are centrilobular nodules, ground-glass opacities, and thickening of the bronchial walls, which predominate in the upper lobes. In lower fields can be seen patchy areas of low attenuation, which correspond to areas of air trapping. Page 9 of 38

10 Fig. 7: RB-ILD in a 49-year-old man with a 20 pack-year smoking history. Axial and coronal CT images of the upper lung lobes shows centrilobular nodules (blue area) and patchy ground-glass opacities (yellow area). References: - Malaga/ES Acute Interstitial Pneumonia (Fig. 8) Page 10 of 38

11 Fig. 8: Summary of Acute Interstitial Pneumonia. References: - Malaga/ES Epidemiological and clinical data - Clinical features include a wide age range, with a mean of 50 years old. Patients often have a history of a prior illness suggestive of a viral upper respiratory infection and present with myalgia, arthralgia, fever, chills, and malaise. Severe exertional dyspnea develops over days. The patient's condition usually progresses to respiratory failure that requires mechanical ventilation and corticosteroid therapy, with the development of adult respiratory distress syndrome. Pathology - The histologic findings include a diffuse distribution with a uniform temporal appearance. In the exudative phase, hyaline membranes, edema, and acute interstitial inflammation are also evident. In the organizing phase, organizing fibrin, loose organizing fibrosis within alveolar lumens with incorporation within alveolar septa, and type II pneumocyte hyperplasia are seen. Thrombi are common in small to medium-sized pulmonary arterioles. If the patient survives, the lung architecture may be partially restored. In other cases, the lungs have extensive fibrosis. Page 11 of 38

12 CT findings - Radiological findings are classified as: a) acute or exudative phase, characterized by areas of ground glass with mosaic pattern that can consolidate in the dependent areas of the lung (Fig. 9), b) late phase, associated with lung architectural distortion, traction bronchiectasis, and cysts. Fig. 9: Exudative phase of AIP in a 42-year-old man. Axial and coronal CT images show bilateral ground-glass opacities and consolidation. References: - Malaga/ES The few patients who survive have residual changes in CT as areas of hypoattenuation, reticular opacities and parenchymal distortion in non-dependent areas or extensive pulmonary fibrosis. Prognosis - AIP has a high mortality, around 80-90%, because of fulminant respiratory failure unresponsive to steroid therapy effectively. Lymphoid Interstitial Pneumonia (Fig. 10) Page 12 of 38

13 Fig. 10: Summary of Lymphoid Interstitial Pneumonia. References: - Malaga/ES Epidemiological and clinical data - It is most often associated with collagen vascular disease, immunodeficiency, and Sjögren syndrome. Idiopathic lymphoid interstitial pneumonia is very rare. It is more common in women and in those who are years old. An insidious onset of cough and dyspnea may be accompanied by fever, weight loss, and arthralgia. Pathology - The histologic findings include interstitial infiltration of involved areas including alveolar septa and bronchioles; infiltrates composed of mostly lymphocytes, plasma cells, and macrophages; and lymphoid follicles. These histologic features have a predominantly alveolar septal distribution. CT findings (Fig. 11) - Consist of ground-glass pattern, poorly defined centrilobular nodules, perilymphatic interstitium thickening, multiple intrapulmonary cysts and mediastinal lymphadenopathy. Page 13 of 38

14 The ground-glass pattern and the presence of centrilobular nodules are the most representative features of LIP. Fig. 11: LIP in a 37-year-old woman. Axial CT images show diffuse ground-glass opacity with multiple cysts and reticular abnormalities. References: - Malaga/ES Nonspecific Interstitial Pneumonia (Fig. 12) Page 14 of 38

15 Fig. 12: Summary of Nonspecific Interstitial Pneumonia. References: - Malaga/ES Epidemiological and clínical data - Includes diffuse interstitial lung diseases with pathological changes that are not characteristic of other types of idiopathic interstitial pneumonias. Two types can be distinguished: inflammatory and fibrotic form. The mean age range of onset is years. Duration of symptoms is 6 months to 3 years. Patients usually present with breathlessness, cough, and fatigue, with weight loss being reported in almost half of the cases. Pathology - It manifests histologically with two different patterns: cellular or fibrosing. The cellular pattern is characterized by mild to moderate interstitial chronic inflammation and interstitial fibrosis with loose fibrillar collagen. The fibrosing pattern is manifest as chronic interstitial inflammation obscured by interstitial fibrosis (with dense collagen), a temporal homogeneous pattern, and occasional focal honeycomb fibrosis. CT findings (Fig. 13) - The most important and characteristic CT finding is the presence of ground-glass attenuation, irregular linear or reticular areas of attenuation with associated Page 15 of 38

16 bronchiectasis and bronchiolectasis. Honeycomb lung and consolidation are seen infrequently. Abnormalities are bilateral, symmetric, and subpleural in distribution. Fig. 13: Axial CT images show bilateral ground-glass opacities with peribroncovascular distribution (orange area) and irregular linear opacities with subpleural distribution (blue area). References: - Malaga/ES It would be very important to differentiate between cellular NSIP and fibrotic NSIP, because cellular form has better prognosis. There is an overlap between the CT findings of these subtypes; however cellular NSIP is infrequently seen with subpleural distribution and has a higher proportion of ground-glass abnormalities. Cryptogenic Organizing Pneumonia (Fig. 14) Page 16 of 38

17 Fig. 14: Summary of Cryptogenic Organizing Pneumonia. References: - Malaga/ES Epidemiological and clínical data - It is often secondary to a known cause such as rheumatoid arthritis, viral pneumonia, or drug reactions. The term cryptogenic organizing pneumonia (formerly bronchiolitis obliterans organizing pneumonia) is used when the histologic features of the organizing pneumonia pattern are demonstrated and the cause is idiopathic. Patients (mean age, 55 years old) usually present with variable degrees of productive cough and dyspnea and short illness duration of less than 3 months. Weight loss, sweats, chills, intermittent fever, and myalgia are common. Pathology - It is distinguished by patchy areas of consolidation characterized by polypoid plugs of loose organizing connective tissue with or without endobronchiolar intraluminal polyps. The architecture of the lung is preserved, and all the connective tissue is the same age. Inflammation is mild or moderate. Page 17 of 38

18 CT findings - Consist of consolidation and ground-glass attenuation with mild bronchial dilatation seen in regions of consolidation. The distribution is subpleural or peribronchial. Areas may be associated ground-glass attenuation. The consolidations can be migratory even without treatment (Fig. 15). Fig. 15: COP in a 49-year-old man. Axial CT images show peripherally located consolidation with air bronchograms (green area). References: - Malaga/ES An unusual CT feature encountered in COP is crescentic or ring-shaped opacities surrounding areas of ground-glass opacification, known as the reversed halo sign (Fig. 16). Page 18 of 38

19 Fig. 16: Atypical appearances of COP in a 43 years-old woman. Axial CT images show the "reversed halo" sign (red circles), reticular pattern and ground-glass opacities with peribroncovascular distribution. References: - Malaga/ES In some cases CT findings consist of pulmonary nodules, solitary mass or multiple masses (15 %) which can sometimes be cavitated. The presence of bandlike opacities, seen as either linear opacities extending in a radial manner along the line of a bronchus toward the pleura, intimately related to bronchi, or linear opacities occurring in a peripheral location bearing no relationship to the bronchi, was recorded. DIFFERENTIAL DIAGNOSIS OF UIP A key point is the distinction of the NIU from the rest of NIP, in the fact that the diagnosis of FIP carries a significantly worse prognosis than the rest, showing survival rates at 5 years of 14-40%. Page 19 of 38

20 The image data that will allow us to distinguish DIP, NSIP and UIP are the existence of peripheral reticular abnormalities in upper lobes, the existence and extent of honeycombing and the degree of ground-glass opacities (Fig 17). Fig. 17: Differential diagnosis of UIP. (A) Reticular abnormalities in upper lobes are shown in UIP, but are not present in DIP or NSIP. (B) Ground-glass opacities are seen in DIP and NSIP, but are less common in UIP. (C) Honeycombing is typical of UIP, is less extensive in NSIP and is not present in DIP. References: - Malaga/ES Images for this section: Page 20 of 38

21 Fig. 2: Summary of Idiopathic Pulmonary Fibrosis. Fig. 3: IPF in a 68-year-old man with mild dyspnea. Axial CT images show honeycombing (orange area), reticular pattern (blue area) and traction bronchiectasis (yellow area). Page 21 of 38

22 Fig. 4: Summary of Desquamative Interstitial Pneumonia Fig. 5: DIP in a 57-year-old man. Axial and coronal CT images of the lower lung lobes shows extensive bilateral ground-glass opacities (green area). Page 22 of 38

23 Fig. 6: Summary of Respiratory Bronchiolitis-associated Interstitial Lung Disease. Page 23 of 38

24 Fig. 7: RB-ILD in a 49-year-old man with a 20 pack-year smoking history. Axial and coronal CT images of the upper lung lobes shows centrilobular nodules (blue area) and patchy ground-glass opacities (yellow area). Page 24 of 38

25 Fig. 8: Summary of Acute Interstitial Pneumonia. Page 25 of 38

26 Fig. 9: Exudative phase of AIP in a 42-year-old man. Axial and coronal CT images show bilateral ground-glass opacities and consolidation. Page 26 of 38

27 Fig. 10: Summary of Lymphoid Interstitial Pneumonia. Fig. 11: LIP in a 37-year-old woman. Axial CT images show diffuse ground-glass opacity with multiple cysts and reticular abnormalities. Page 27 of 38

28 Fig. 12: Summary of Nonspecific Interstitial Pneumonia. Fig. 13: Axial CT images show bilateral ground-glass opacities with peribroncovascular distribution (orange area) and irregular linear opacities with subpleural distribution (blue area). Page 28 of 38

29 Fig. 14: Summary of Cryptogenic Organizing Pneumonia. Page 29 of 38

30 Fig. 15: COP in a 49-year-old man. Axial CT images show peripherally located consolidation with air bronchograms (green area). Page 30 of 38

31 Fig. 16: Atypical appearances of COP in a 43 years-old woman. Axial CT images show the "reversed halo" sign (red circles), reticular pattern and ground-glass opacities with peribroncovascular distribution. Page 31 of 38

32 Fig. 17: Differential diagnosis of UIP. (A) Reticular abnormalities in upper lobes are shown in UIP, but are not present in DIP or NSIP. (B) Ground-glass opacities are seen in DIP and NSIP, but are less common in UIP. (C) Honeycombing is typical of UIP, is less extensive in NSIP and is not present in DIP. Page 32 of 38

33 Conclusion - IIPs are rare. Nevertheless, they are considered prototypes of the much more common secondary interstitial pneumonias that can be encountered in frequent disorders (sarcoidosis, vasculitis, and connective tissue diseases). - The classification of IIPs is based on histologic criteria, but those histologic patterns are closely associated with imaging patterns that correlate well with histologic findings. - Establishing the final diagnosis of IIPs requires close communication and interaction between clinicians, radiologists, and pathologists. - High-resolution CT is indicated in virtually all patients suspected to have IIPs. - The key role of the radiologist is to identify patients with UIP and differentiate them from patients with other IIPs, because UIP has a substantially poorer prognosis than other IIPs. - In all patients suspected to have IIPs who do not show the typical clinical and radiologic features of UIP, surgical lung biopsy should be performed. Page 33 of 38

34 Fig. 18: Diagram of idiopathic interstitial pneumonias. References: - Malaga/ES Page 34 of 38

35 Fig. 19: Illustrations of idiopathic interstitial pneumonias. References: - Malaga/ES Images for this section: Page 35 of 38

36 Fig. 18: Diagram of idiopathic interstitial pneumonias. Page 36 of 38

37 Fig. 19: Illustrations of idiopathic interstitial pneumonias. Page 37 of 38

38 Personal information - S. Claret Loaiza, Department of Radiology, Hospital Carlos Haya, Av Carlos Haya s/ n, Málaga (España). - M.C. Cañete Moslero, Department of Radiology, Hospital Carlos Haya, Av Carlos Haya s/n, Málaga (España). - R. Carreño-Gonzalez, Department of Radiology, Hospital Carlos Haya, Av Carlos Haya s/n, Málaga (España). - C. de la Torre, Department of Radiology, Hospital Carlos Haya, Av Carlos Haya s/n, Málaga (España). References - Wittram C et al. CT-Histologic Correlation of the ATS/ERS 2002 Classification of Idiopathic Interstitial Pneumonias. RadioGraphics 2003; 23(5): Lynch DA et al. Idiopathic Interstitial Pneumonias: CT Features. Radiology 2005; 236(1): Attili AK et al. Smoking-related Interstitial Lung Disease: Radiologic-Clinical-Pathologic Correlation. RadioGraphics 2008; 28(5): Ujita M et al. Organizing Pneumonia: Perilobular Pattern at Thin-Section CT. Radiology 2004; 232(3): Mueller-Mang C et al. What Every Radiologist Should Know about Idiopathic Interstitial Pneumonias. RadioGraphics 2007; 27(3): Encinas J et al. Aproximación al diagnóstico radiológico de las neumonías intersticiales idiopáticas. Hallazgos en tomografía computarizada de alta resolución. Radiologia 2010; 54(1): J. Ancochea et al. Consenso para el diagnóstico de las neumonías intersticiales idiopáticas. Arch Bronconeumol 2010;46(10):2-21. Page 38 of 38