Comparison between Community-Acquired Pneumonia and Post-Obstructive Pneumonia Associated with Endobronchial Tumors

Comparison between Community-Acquired Pneumonia and Post-Obstructive Pneumonia Associated with Endobronchial Tumors | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Comparison between Community-Acquired Pneumonia and Post-Obstructive Pneumonia Associated with Endobronchial Tumors Wenwen Yu, Yubo Shi, Qingsong Zheng, Jianwu Chen, Xie Zhang, Ali Chen, and 6 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4705907/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 28 Nov, 2024 Read the published version in BMC Pulmonary Medicine → Version 1 posted 4 You are reading this latest preprint version Abstract Background Endobronchial tumors can infiltrate the bronchial wall or protrude into the bronchial lumen, causing post-obstructive pneumonia (POP). Differentiating between POP and community-acquired pneumonia (CAP) is challenging due to similar clinical, laboratory, and imaging findings, which can delay the diagnosis and treatment of endobronchial tumors. Methods We compared general demographic information, laboratory test results, lung CT images, bronchoscopic observations, pathological findings between the POP group and the CAP group. Results 1. The POP group consisted mainly of older individuals (mean age 69 vs. 56 years; P < 0.05), males (93.4% vs. 47.1%; P < 0.05), and smokers (67.2% vs. 14.7%; P < 0.05). Clinical symptoms varied, with chest pain (23.0% vs. 11.8%; P < 0.05) and hemoptysis (26.2% vs. 10.8%; P < 0.05) more prevalent in the POP group. MSCT showed that bronchial wall thickening, bronchial stenosis, occlusion, obstructive emphysema, mucoid impaction, and endobronchial shadows occurred more frequently in POP, while consolidation and exudation shadows were predominant in CAP (P < 0.05). 2. In the POP group, neoplasms were the most frequent bronchoscopic findings (57 cases, 93.44%), especially in the upper lungs. Squamous cell carcinoma was the primary pathological type (52 cases, 85.25%). The average delay in diagnosing endobronchial tumors was 214.8 days. In the POP group, 34 cases (55.74%) had abnormal CT images in the past and did not undergo bronchoscopy, resulting in delayed diagnosis. 3. Factors such as gender, age, bronchial occlusion, stenosis, mucus embolism, and intraluminal shadow were determined to be independent risk factors for endobronchial tumors (P 1). Conclusions Endobronchial tumors combined with POP are easily misdiagnosed as CAP in the early stage. Factors like bronchial occlusion, stenosis, mucus embolism, and intraluminal shadows on MSCT are significant independent risk factors for these tumors, indicating the need for early bronchoscopy. Post-obstructive pneumonia Community acquired pneumonia Endobronchial tumor Figures Figure 1 Figure 2 Introduction Post-obstructive pneumonia (POP) is a type of pulmonary infection that arises due to bronchial obstruction, which may be caused by lung and tracheobronchial tumors, intratracheal foreign bodies, among other factors [ 1 ]. In advanced lung cancer patients, POP is common, with incidence rates ranging from 40%-55%, leading to a poor prognosis and elevated mortality [ 2 ]. Especially in central type lung cancer, early-stage intraluminal obstruction can often be treated effectively if detected early. However, the subtle onset and nonspecific symptoms of early-stage lung cancer make it difficult to differentiate from community-acquired pneumonia. Notably, malignancies are identified in about 2% of patients admitted with community-acquired pneumonia [ 3 ], posing a significant risk of misdiagnosis or delayed diagnosis [ 4 ]. Thus, this retrospective analysis is designed to discern the prevalent clinical, imaging, and bronchoscopic features of POP associated with endobronchial tumors versus CAP, aiming to identify endobronchial tumors as early as possible through characteristic CT imaging and enhance the early detection of endobronchial tumors and improve outcomes. Methods Study design and participants In this retrospective, single-center cohort study at Affiliated Yueqing Hospital of Wenzhou Medical University, Zhejiang Province, China, 163 adult patients (aged ≥ 18 years) were enrolled from April 2014 to December 2022. All participants were diagnosed with pneumonia based on Multi-slice Spiral computed tomography (MSCT) findings and received antibiotic treatment. The patients were divided into two groups according to the bronchoscopic biopsy results: 61 with post-obstructive pneumonia and 102 with community-acquired pneumonia. Inclusion criteria included: 1) patients showing inflammatory changes on CT scans with comprehensive clinical and imaging data, and 2) those who underwent bronchoscopy. Exclusion criteria encompassed 1) coagulation dysfunction or severe hematologic conditions, 2) malignant arrhythmias, 3) organ dysfunction or failure (heart, brain, kidney, lung, or other systemic organs), 4) severe pulmonary hypertension, 5) mental health disorders, and 6) individuals with bronchiectasis, chronic obstructive pulmonary disease, or a history of lung surgery. Pulmonary infection was defined by new or worsening pulmonary infiltrates plus at least two symptoms: subjective or documented fever (> 37.4°C), increased cough, sputum production, dyspnea, pleuritic chest pain, confusion, crackles, leukocytosis (WBC count > 12,000 cells/µL), or leukopenia (< 6,000 cells/µL). Post-obstructive pneumonia was identified by radiographic evidence of a pulmonary infiltrate beyond an obstructed bronchus. Data collection Clinical and demographic data were collected and are detailed in Table 1 . This data included age, sex, height, weight, smoking status, medical history, and symptoms such as cough, expectoration, hemoptysis, chest pain, dyspnea, wheezing, and fever. At admission, a comprehensive set of tests was documented: complete blood count, procalcitonin (PCT), C-reactive protein (CRP), arterial blood gas analysis, and tumor markers including carcinoembryonic antigen (CEA), cytokeratin 19 fragment (CYFRA21-1), squamous cell carcinoma antigen (SCC), and neuron-specific enolase (NSE). Lung imaging was performed using UCT 710 60-slice and Philips Ingenuity 64-slice CT scanners, capturing the entire lung from apex to base. Bronchoscopic evaluations were conducted using an Olympus BF-Q290 bronchoscope to inspect the trachea, bronchi, and distal bronchi, with biopsies taken of any detected abnormalities for subsequent histopathological analysis. Statistical analysis Statistical analysis was conducted using IBM SPSS Statistics Software (version 27.0; IBM, New York, USA). Data were tested for normality and variance homogeneity. Normally distributed continuous variables were reported as mean ± standard deviation (minimum-maximum) and analyzed using the unpaired two-tailed Student's t-test. Skewed continuous variables were presented as medians (interquartile ranges) and analyzed using the Mann-Whitney U test. Categorical variables were shown as number (%) and assessed using the χ² test or Fisher’s exact test between the POP and CAP groups. Univariable and multivariable logistic regression models were employed to identify risk factors for endobronchial lesions, excluding variables without significant intergroup differences. P < 0.05 was deemed statistically significant. Results Comparison of clinical and demographic data between patients with post-obstructive pneumonia and community-acquired pneumonia Clinical and demographic data were collected and are summarized in Table 1. Post-obstructive pneumonia with endobronchial tumors was more common in elderly individuals (69 years vs. 56 years; P < 0.05), males (93.4% vs. 47.1%; P < 0.05), and smokers (67.2% vs. 14.7%; P < 0.05). Both groups displayed symptoms of cough and expectoration with no significant difference (P < 0.05). However, hemoptysis and chest pain were more frequent in the post-obstructive pneumonia group (26.2% vs. 10.8% and 23.0% vs. 11.8%, respectively; P < 0.05). In contrast, sputum production and fever were more prevalent in the community-acquired pneumonia group (68.9% vs. 83.3% and 14.8% vs. 46.1%, respectively; P < 0.05). The post-obstructive pneumonia group showed significantly higher levels of carcinoembryonic antigen, squamous cell carcinoma antigen, and cytokeratin 19 fragment compared to the community-acquired pneumonia group. There was no significant difference in procalcitonin, C-reactive protein, and neuron-specific enolase levels between the groups. More instances of bronchial wall thickening (19.7% vs. 2%; P < 0.05) and stenosis (52.4% vs. 15.6%; P < 0.05) were observed in the post-obstructive group. In contrast, bronchial occlusion (65.5% vs. 7.8%; P < 0.05), intraluminal masses (47.5% vs. 7.8%; P < 0.05), and bronchial mucus embolism (31.1% vs. 2.9%; P < 0.05) were more prevalent in the community-acquired pneumonia group, which also showed a higher incidence of pulmonary consolidation and/or exudative changes. Pleural effusion and lymphadenopathy were present in both groups without a significant difference. Subgroup analysis of patients with post-obstructive pneumonia Bronchoscopy confirmed the presence of malignant tumors, hamartomas, or dysplasia in patients with post-obstructive pneumonia. Among these patients, the bilateral upper lungs were predominantly affected in 59.02% of 61 cases. Specifically, the right lung was involved in 39 cases (63.93%), with 21 (34.43%) in the right upper lung. And the left lung was involved in 22 (36.07%), with 15 (24.59%) in the left upper lung (Table 2 and Figure 1). Bronchoscopy identified bronchial infiltration, stenosis, occlusion, and intraluminal neoplasms in the POP group, noting bronchial occlusion in 56 cases (91.8%), intraluminal neoplasms in 57 cases (93.44%), bronchial infiltration in 24 cases (39.34) and bronchial stenosis in 5 cases (8.20%). Pathology revealed squamous cell carcinoma in 52 cases (85.25%), adenocarcinoma in 3 (4.92%), hamartoma in 2 (3.28%), carcinoid in 2 (3.28%), small cell lung cancer in 1 (1.64%), and dysplasia in 1 (1.64%) (Figure 1). Univariate logistic regression analysis was applied to statistically significant variables, with those showing P 1 progressing to multivariate analysis. This analysis identified elderly individuals, males, and CT imaging findings of bronchial obstruction, bronchial stenosis, bronchial mucus embolism, and intrabronchial shadows as independent risk factors for endobronchial tumors (P < 0.05) , as shown in Table 3. The time from the first appearance of imaging abnormalities in CT to the diagnosis of endobronchial tumors through bronchoscopy is defined as the delay time. If an abnormality is reported by CT and immediate hospitalization or outpatient bronchoscopy is performed, the delay time is 0. We found that the average delay time in the POP group is 214.8 days (range: 0-1170 days). In the POP group, 34 patients (55.74%) had abnormal CT images in the past and did not undergo bronchoscopy, resulting in delayed diagnosis. Thus, prompt recognition of specified imaging characteristics is vital to reduce diagnostic delays. In the post-obstructive pneumonia group, bronchial occlusion imaging showed high sensitivity (65.5%) and specificity (92.2%). Sensitivity increased to 96.7% when combined with bronchial stenosis, but no significant enhancement was noted with other imaging features(Table 4). Case presentation A 68-year-old male experienced intermittent cough and fever for the past five days. Physical examination identified diminished breath sounds in the right lower lung. A chest CT on July 20, 2022, depicted a right hilar mass, right lower lobe atelectasis, nodules in the right main trachea and bronchus, and right lower lung inflammation (Fig. 2A). A bronchoscopy conducted on July 26, 2022, revealed a smooth neoplasm at the lower lobe bronchus ostium of the right lung (Fig. 2B), diagnosed as squamous cell carcinoma through pathological examination (Fig. 2C). The patient underwent surgical intervention. A retrospective review of a chest CT from October 20, 2020, at a different facility showed narrowing at the right lower bronchial ostium (Fig. 2D), indicating a diagnostic delay of 644 days for this patient. Table 1. Comparison of patient data between the POP group and the CAP group Characteristic POP group (n=61) CAP group (n=102) P Value Demographics and comorbidities Age, y a 69(58-80) 59(38-80) <0.001 Body mass index, kg/m2 a 21.58±2.45 22.11±3.27 0.282 Male sex 57(93.4) 48(47.1) <0.001 Smoking 41(67.2) 15(14.7) <0.001 Comorbidities 30(49.2) 60(58.8) 0.257 Clinical features Cough 52(85.2) 94(92.2) 0.190 Sputum 42(68.9) 85(83.3) 0.034 Hemoptysis 16(26.2) 11(10.8) 0.016 Chest pain 14(23.0) 12(11.8) 0.049 Dyspnea 9(14.8) 15(14.7) 1.000 Wheezing 5(8.2) 9(8.8) 1.000 Temperature >37.4°C 9(14.8) 47(46.1) <0.001 Laboratory features C-reactive protein, mg/L a 8.35(5.00-102.86) 36.96(5.54-94.63) 0.228 Procalcitonin, ng/mL a 0.25(0.09-0.25) 0.25(0.05-0.25) 0.013 White blood cell count, cells/µL a 7.93(5.62-9.03) 7(5.42-9.79) 0.325 Lymphocyte count, cells/µL a 1.34(1.11-1.94) 1.4(1.15-1.78) 0.715 Neutrophil Count, cells/µL a 5.65(3.72-6.79) 4.54(3.09-7.22) 0.469 Platelet count, cells/µL a 228.5(196.50-315.75) 263(196-319) 0.907 Globular value, g/L a 128.5(117.5-139.25) 126(112-135) 0.075 CEA, ng/mL a 2.73(2.03-4.62) 1.67(1.23-2.42) <0.001 SCC, ng/mL a 1.59(1.91) 1.04(0.78-1.41) <0.001 CYFRA21-1, ng/mL a 4.06(2.56-6.04) 1.98(1.55-2.89) <0.001 NSE, ng/mL a 12.90(10.21-17.27) 13(10.91-15.19) 0.853 Radiographic features Consolidation 7(11.5) 46(45.1) <0.001 Exudation 30(49.2) 90(88.2) <0.001 Emphysema 8(13.11) 1(1.0) 0.002 Bronchial wall thickening 12(19.7) 2(2.0) <0.001 Bronchial occlusion 40(65.6) 8(7.8) <0.001 Bronchial-stenosis 32(52.5) 16(15.7) <0.001 Atelectasis 7(11.5) 7(6.9) 0.388 Bronchial mucus embolism 19(31.1) 3(2.9) <0.001 Shadow in the lumen of the bronchi 29(47.5) 8(7.8) <0.001 Pleural effusion 2(3.3) 10(9.8) 0.213 Lymphadenectasis 15(24.6) 34(33.3) 0.291 Data are shown as No. (%) of patients and refer to values at the time of admission, unless stated otherwise. Abbreviations: CEA, carcinoembryonic antigen; SCC, squamous cell carcinoma antigen; CYFRA21-1, cytokeratin 19 fragment; NSE, neuron-specific enolase. a Median (interquartile range). Table 2. Bronchoscopic findings in the POP group Site POP group (n=61) (n，%) Right upper lobe Anterior segment 8，13.11% Apical segment 6，9.84% Posterior segment 7，11.48% Right middle lobar bronchus 1，1.64% Right inferior lobe Dorsal segment 8，13.11% Basal segment 9，14.75% Left upper lobe Anterior segment 8，13.11% Intrinsic bronchus 6，9.83% Left upper lobe Lingular bronchi 1，1.64% Left inferior lobe Basal segment 5，8.20% Dorsal segment 2，3.28% Table 3. Risk factors of endobronchial tumor complicated with POP Index Single factor OR P Value Multiple factor OR P Value Demographics Gender 16.03 < 0.001 12.335 0.014 Age 1.088 < 0.001 1.289 0.011 Smoking history 1.078 < 0.001 1.034 0.072 Laboratory features PCT 2.386 0.132 CEA 1.925 < 0.001 1.195 0.495 SCC 1.425 0.011 1.034 0.904 CYFRA21-1 1.426 < 0.001 1.248 0.181 Radiographic features Consolidation 0.158 < 0.001 Exudation 0.129 < 0.001 Emphysema 15.245 0.011 14.253 0.065 Bronchial wall thickening 12.245 0.001 5.283 0.167 Bronchial occlusion 22.381 < 0.001 61.349 0.001 Bronchial stenosis 5.931 < 0.001 11.032 0.001 Bronchial mucus embolism 14.929 < 0.001 20.858 0.013 Shadow in the lumen of the bronchi 10.648 < 0.001 5.758 0.038 Table 4. Diagnostic value of single and combined imaging findings in endobronchial tumor Radiographic features Sensitivity (%) Specificity(%) Jorden index Bronchial occlusion 65.5 92.2 0.577 Bronchial-stenosis 52.5 84.3 0.368 Bronchial mucus embolism 31.1 97.1 0.282 Shadow in the lumen of the bronchi 47.5 92.2 0.397 Occlusion/Stenosis 96.7 78.4 0.751 Occlusion//Shadow in the lumen 73.8 79.4 0.532 Occlusion/Shadow in the lumen 82.0 88.2 0.702 Sstenosis/Occlusion/Shadow in the lumen 98.4 77.5 0.759 Stenosis/Occlusion/Bronchial mucus embolism 98.4 78.4 0.768 Stenosis/Occlusion/Shadow in the lumen/Bronchial mucus embolism 98.4 77.5 0.759 Discussion According to the WHO International Agency for Research on Cancer, lung cancer is the leading cause of cancer-related morbidity and mortality worldwide [5]. This is largely due to 85% of patients being diagnosed at advanced stages, missing early diagnostic and treatment opportunities [6]. Lung cancer primarily affects older men, with smoking as the foremost risk factor, although the influence of other factors like environmental pollution and exposure to radioactive substances is on the rise [7]. Endobronchial lesions are potential precursors to central airway lung carcinomas. Early identification and treatment of these lesions can prevent their progression to invasive carcinoma. Of the 61 patients with obstructive pneumonia and endobronchial tumors, 57 were male, and 41 had a smoking history. Univariate analysis identified gender and smoking as independent risk factors for endobronchial tumors, aligning with prior research. While quitting smoking reduces lung cancer risk, former smokers still face a risk nine times greater than non-smokers [8]. Chiaki Endo et al. [9] analyzed 251 patients with early-stage central airway lung cancer, 207 of whom underwent surgical resection. They reported 5-year and 10-year survival rates post-treatment of 96.7% and 94.9%, respectively. Early diagnosis and thorough resection of central pneumonia are crucial for enhancing lung cancer survival rates [10]. MSCT is essential in assessing endobronchial lesions, providing valuable information on tracheal stenosis, bronchial wall thickening, obstruction, tracheobronchial malacia, and both benign and malignant bronchial tumors. Its application in screening high-risk individuals significantly lowers the relative risk of dying from lung cancer [11]. Guidelines recommend MSCT for early diagnosis and screening in high-risk groups [12]. Nonetheless, MSCT may overlook endobronchial lesions, highlighting the need for integrating characteristic imaging features with bronchoscopy to ensure early lesion detection. Tumor growth within the bronchial lumen can lead to irregular stenosis, thickening, and occlusion of the bronchial wall, manifesting as indirect imaging signs like obstructive pneumonia, emphysema, and atelectasis. Yet, clinicians often misinterpret post-obstructive pneumonia as community-acquired pneumonia, resulting in missed early diagnostic and treatment opportunities for endobronchial tumors. Unlike community-acquired pneumonia, post-obstructive pneumonia stems from bronchial obstruction, causing impaired drainage of distal secretions or atelectasis, sometimes with a secondary infection. The term "postobstructive pneumonia" was coined in the 1970s, replacing "obstructive pneumonitis"[13]. McDonald et al. [14] characterized radiographic opacity from bronchial obstruction by a tumor as post-obstructive pneumonitis. Although research on obstructive pneumonia is limited, evidence suggests many patients initially diagnosed with community-acquired pneumonia actually have underlying lung cancer[15,16]. Early detection hinges on understanding normal bronchial anatomy, comparing bilateral pulmonary bronchi, and utilizing advanced imaging techniques. Prompt bronchoscopy and biopsy are pivotal for enhancing early diagnosis rates. Certain rare tumors, like lung carcinoids, typically necessitate bronchoscopy for accurate diagnosis due to the limitations of imaging techniques such as CT or PET/CT[17]. Misidentifying intraluminal bronchial tumors and obstructive pneumonia can worsen endobronchial obstruction, increasing the risk of recurrent pulmonary infections, tumor progression, and higher mortality rates. Post-obstructive pneumonia patients often endure longer symptom durations and higher mortality than those with community-acquired pneumonia[18]. While community-acquired pneumonia imaging typically shows consolidation and exudation, obstructive pneumonia features distinct signs like bronchial wall thickening, occlusion, stenosis, obstructive emphysema, bronchial mucus embolism, and intraluminal shadows. Significantly, bronchial occlusion is highly specific for tumor screening, with imaging of bronchial stenosis and/or occlusion aligning closely with bronchoscopic findings for high sensitivity. Endobronchial tumors include both benign and malignant types, with the latter encompassing squamous cell carcinoma, adenocarcinoma, carcinoid, adenoid cystic carcinoma, and metastatic tumors. Benign varieties consist of hamartomas, neurogenic tumors, and lipomas[19,20]. Endobronchial resection is often the preferred method for diagnosing and treating these tumors. In our study, bronchial occlusion and neoplasms were the predominant bronchoscopic findings in patients with post-obstructive pneumonia, representing a significant portion of the cases. Squamous cell carcinoma emerged as the leading pathological type among these lesions, highlighting the necessity of early detection of imaging signs indicative of squamous cell carcinoma. Notably, post-obstructive pneumonia seems to occur more frequently in patients with squamous cell carcinoma than in those with adenocarcinoma, aligning with previous research findings. However, this study has several limitations. First, it is a single-center study conducted at Affiliated Yueqing Hospital of Wenzhou Medical University, potentially limiting the generalizability of the results to other centers or populations. Furthermore, its retrospective nature means it relies on historical data, which may impact the accuracy of the findings. In conclusion, There is a possibility of misdiagnosis as community-acquired pneumonia when endobronchial tumors associated with post-obstructive pneumonia. Factors like bronchial occlusion, stenosis, mucus embolism, and intraluminal shadows on CT are significant independent risk factors for endobronchial tumors. Clinicians and radiologists should be vigilant for bronchial abnormalities in pneumonia patients on imaging, particularly when antibiotic treatment is ineffective, and undergo bronchoscopy as early as possible to determine endobronchial tumors. Declarations Acknowledgements We wish to acknowledge all the participants, medical-, nursing-, and technical-staff who has been involved in collecting the samples for this study. Author contributions W. Y., Y. L., Y. S. performed the research, collected and analyzed the data and wrote the paper. X.Z., A.C., Z. Y., and W.Z. contributed to sample collection. Q. Z. , J. C. , L. Z.and H.Y., L.L.contributed to supervision of this study and revision of the manuscript. All authors reviewed the manuscript. Funding This study has not been funded. Data availability The data that support the fndings of this study are available from the corresponding author upon reasonable request. Ethics approval and consent to participate The present study was conducted in accordance with the amended Declaration of Helsinki. The Ethics Committee of Affiliated Yueqing Hospital of Wenzhou Medical University approved the protocol of this retrospective study (approval number: YQYY202300206), and granting a waiver of informed consent due to the retrospective nature of data collection. Consent to publish Not applicable. Competing interests The authors declare no competing interests. References Torres A, Ferrer M. Editorial Commentary: Distinguishing Postobstructive Lung Infection From Community-Acquired Pneumonia [J]. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America 2016, 62(8):962-963. Moretti M, Wellekens S, Dirkx S, et al. Features of post-obstructive pneumonia in advanced lung cancer patients, a large retrospective cohort [J]. Infectious diseases (London, England) 2023, 55(2):149-157. Rolston KVI, Nesher L. 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Stevic R, Milenkovic B. Tracheobronchial tumors [J]. Journal of thoracic disease 2016, 8(11):3401-3413. Insler JE, Seder CW, Furlan K, et al. Benign Endobronchial Tumors: A Clinicopathologic Review [J]. Frontiers in surgery 2021, 8:644656. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 28 Nov, 2024 Read the published version in BMC Pulmonary Medicine → Version 1 posted Editorial decision: Revision requested 17 Jul, 2024 Editor assigned by journal 16 Jul, 2024 Submission checks completed at journal 16 Jul, 2024 First submitted to journal 08 Jul, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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University","correspondingAuthor":false,"prefix":"","firstName":"Weilong","middleName":"","lastName":"Zhou","suffix":""},{"id":328204488,"identity":"dca9804c-490f-43fe-b582-02c2f428112f","order_by":8,"name":"Li Lin","email":"","orcid":"","institution":"Affiliated Yueqing Hospital of Wenzhou Medical University","correspondingAuthor":false,"prefix":"","firstName":"Li","middleName":"","lastName":"Lin","suffix":""},{"id":328204489,"identity":"7744ec52-8ba3-4816-96ef-6fa7f8de5a06","order_by":9,"name":"Legui Zheng","email":"","orcid":"","institution":"Affiliated Yueqing Hospital of Wenzhou Medical University","correspondingAuthor":false,"prefix":"","firstName":"Legui","middleName":"","lastName":"Zheng","suffix":""},{"id":328204490,"identity":"acdb59df-82c3-4ab5-9959-6ad3b9e74dd6","order_by":10,"name":"Hua Ye","email":"","orcid":"","institution":"Affiliated Yueqing Hospital of Wenzhou Medical University","correspondingAuthor":false,"prefix":"","firstName":"Hua","middleName":"","lastName":"Ye","suffix":""},{"id":328204491,"identity":"6d562239-f5d1-43db-b4c9-269b6879d6e6","order_by":11,"name":"Yunlei Li","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAyElEQVRIiWNgGAWjYLCCBwwS9WzsjY0PPxCjmgdEJDBYJPDxHG42liBBS0WCnER6mwAPMVrs+deYSSRUSOSxST5sY5BgsJPTbSBki8QboJYzEsVs0oltDwoYko3NDhDUcsZMIrFNgrFNOrHdQILhQOI24rT8A2qRPNgmwUOUFv4eoJYGiEVEarnBVmyRcEzCmI0nERjIBkT4hb3/8MYbH2rq5OTbjz98+KHCTo6gFgaJDAMkngFOdUiA//gDYpSNglEwCkbBSAYAI389aH08x1YAAAAASUVORK5CYII=","orcid":"","institution":"Affiliated Yueqing Hospital of Wenzhou Medical University","correspondingAuthor":true,"prefix":"","firstName":"Yunlei","middleName":"","lastName":"Li","suffix":""}],"badges":[],"createdAt":"2024-07-08 13:29:14","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4705907/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4705907/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12890-024-03409-8","type":"published","date":"2024-11-28T15:58:08+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":62647288,"identity":"f1fd5973-004c-4a0a-a7a1-fba53b5ac88f","added_by":"auto","created_at":"2024-08-16 21:26:11","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":434227,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003ePathological types and anatomical locations of endobronchial tumors in patients with POP\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-4705907/v1/c8ed4dc9cbf0a4def978abd6.png"},{"id":62647289,"identity":"e65f6a24-8fb7-4ce6-aca0-f0b158df4baa","added_by":"auto","created_at":"2024-08-16 21:26:11","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":931482,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003e(A) A Chest CT (July 20, 2022) revealed a right hilar mass with right lower lobe atelectasis, nodules in the right main trachea, and right lower lobe bronchus, accompanied by inflammation in the right lower lung. (B) Bronchoscopy (July 26, 2022) demonstrated a smooth neoplasm at the ostium of the bronchus in the right lower lobe. (C) Histopathology confirmed squamous cell carcinoma, characterized by tumor cells arranged in a nest-like pattern, featuring large, heterogeneous nuclei and frequent mitotic figures (original magnification ×100). (D) A Chest CT (October 20, 2020) indicated narrowing at the right lower bronchial ostium.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-4705907/v1/cdf4dc05a5920086717d67cd.png"},{"id":70391305,"identity":"d15124a2-fbaf-42c6-ae44-a42bfe545730","added_by":"auto","created_at":"2024-12-02 17:30:41","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3095985,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4705907/v1/6b70d034-35d2-4921-97ab-ac8c819f7902.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Comparison between Community-Acquired Pneumonia and Post-Obstructive Pneumonia Associated with Endobronchial Tumors","fulltext":[{"header":"Introduction","content":"\u003cp\u003ePost-obstructive pneumonia (POP) is a type of pulmonary infection that arises due to bronchial obstruction, which may be caused by lung and tracheobronchial tumors, intratracheal foreign bodies, among other factors [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. In advanced lung cancer patients, POP is common, with incidence rates ranging from 40%-55%, leading to a poor prognosis and elevated mortality [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Especially in central type lung cancer, early-stage intraluminal obstruction can often be treated effectively if detected early. However, the subtle onset and nonspecific symptoms of early-stage lung cancer make it difficult to differentiate from community-acquired pneumonia. Notably, malignancies are identified in about 2% of patients admitted with community-acquired pneumonia [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e], posing a significant risk of misdiagnosis or delayed diagnosis [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Thus, this retrospective analysis is designed to discern the prevalent clinical, imaging, and bronchoscopic features of POP associated with endobronchial tumors versus CAP, aiming to identify endobronchial tumors as early as possible through characteristic CT imaging and enhance the early detection of endobronchial tumors and improve outcomes.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy design and participants\u003c/h2\u003e \u003cp\u003eIn this retrospective, single-center cohort study at Affiliated Yueqing Hospital of Wenzhou Medical University, Zhejiang Province, China, 163 adult patients (aged\u0026thinsp;\u0026ge;\u0026thinsp;18 years) were enrolled from April 2014 to December 2022. All participants were diagnosed with pneumonia based on Multi-slice Spiral computed tomography (MSCT) findings and received antibiotic treatment. The patients were divided into two groups according to the bronchoscopic biopsy results: 61 with post-obstructive pneumonia and 102 with community-acquired pneumonia. Inclusion criteria included: 1) patients showing inflammatory changes on CT scans with comprehensive clinical and imaging data, and 2) those who underwent bronchoscopy. Exclusion criteria encompassed 1) coagulation dysfunction or severe hematologic conditions, 2) malignant arrhythmias, 3) organ dysfunction or failure (heart, brain, kidney, lung, or other systemic organs), 4) severe pulmonary hypertension, 5) mental health disorders, and 6) individuals with bronchiectasis, chronic obstructive pulmonary disease, or a history of lung surgery. Pulmonary infection was defined by new or worsening pulmonary infiltrates plus at least two symptoms: subjective or documented fever (\u0026gt;\u0026thinsp;37.4\u0026deg;C), increased cough, sputum production, dyspnea, pleuritic chest pain, confusion, crackles, leukocytosis (WBC count\u0026thinsp;\u0026gt;\u0026thinsp;12,000 cells/\u0026micro;L), or leukopenia (\u0026lt;\u0026thinsp;6,000 cells/\u0026micro;L). Post-obstructive pneumonia was identified by radiographic evidence of a pulmonary infiltrate beyond an obstructed bronchus.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eData collection\u003c/h2\u003e \u003cp\u003eClinical and demographic data were collected and are detailed in Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e1\u003c/span\u003e. This data included age, sex, height, weight, smoking status, medical history, and symptoms such as cough, expectoration, hemoptysis, chest pain, dyspnea, wheezing, and fever. At admission, a comprehensive set of tests was documented: complete blood count, procalcitonin (PCT), C-reactive protein (CRP), arterial blood gas analysis, and tumor markers including carcinoembryonic antigen (CEA), cytokeratin 19 fragment (CYFRA21-1), squamous cell carcinoma antigen (SCC), and neuron-specific enolase (NSE). Lung imaging was performed using UCT 710 60-slice and Philips Ingenuity 64-slice CT scanners, capturing the entire lung from apex to base. Bronchoscopic evaluations were conducted using an Olympus BF-Q290 bronchoscope to inspect the trachea, bronchi, and distal bronchi, with biopsies taken of any detected abnormalities for subsequent histopathological analysis.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eStatistical analysis was conducted using IBM SPSS Statistics Software (version 27.0; IBM, New York, USA). Data were tested for normality and variance homogeneity. Normally distributed continuous variables were reported as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (minimum-maximum) and analyzed using the unpaired two-tailed Student's t-test. Skewed continuous variables were presented as medians (interquartile ranges) and analyzed using the Mann-Whitney U test. Categorical variables were shown as number (%) and assessed using the χ\u0026sup2; test or Fisher\u0026rsquo;s exact test between the POP and CAP groups. Univariable and multivariable logistic regression models were employed to identify risk factors for endobronchial lesions, excluding variables without significant intergroup differences. P\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was deemed statistically significant.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cstrong\u003eComparison of clinical and demographic data between patients with post-obstructive pneumonia and community-acquired pneumonia\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eClinical and demographic data were collected and are summarized in Table 1. Post-obstructive pneumonia with endobronchial tumors was more common in elderly individuals (69 years vs. 56 years; P \u0026lt; 0.05), males (93.4% vs. 47.1%; P \u0026lt; 0.05), and smokers (67.2% vs. 14.7%; P \u0026lt; 0.05). Both groups displayed symptoms of cough and expectoration with no significant difference (P \u0026lt; 0.05). However, hemoptysis and chest pain were more frequent in the post-obstructive pneumonia group (26.2% vs. 10.8% and 23.0% vs. 11.8%, respectively; P \u0026lt; 0.05). In contrast, sputum production and fever were more prevalent in the community-acquired pneumonia group (68.9% vs. 83.3% and 14.8% vs. 46.1%, respectively; P \u0026lt; 0.05). The post-obstructive pneumonia group showed significantly higher levels of carcinoembryonic antigen, squamous cell carcinoma antigen, and cytokeratin 19 fragment compared to the community-acquired pneumonia group. There was no significant difference in procalcitonin, C-reactive protein, and neuron-specific enolase levels between the groups. More instances of bronchial wall thickening (19.7% vs. 2%; P \u0026lt; 0.05) and stenosis (52.4% vs. 15.6%; P \u0026lt; 0.05) were observed in the post-obstructive group. In contrast, bronchial occlusion (65.5% vs. 7.8%; P \u0026lt; 0.05), intraluminal masses (47.5% vs. 7.8%; P \u0026lt; 0.05), and bronchial mucus embolism (31.1% vs. 2.9%; P \u0026lt; 0.05) were more prevalent in the community-acquired pneumonia group, which also showed a higher incidence of pulmonary consolidation and/or exudative changes. Pleural effusion and lymphadenopathy were present in both groups without a significant difference.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSubgroup analysis of patients with post-obstructive pneumonia\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eBronchoscopy confirmed the presence of malignant tumors, hamartomas, or dysplasia in patients with post-obstructive pneumonia. Among these patients, the bilateral upper lungs were predominantly affected in 59.02% of 61 cases. Specifically, the right lung was involved in 39 cases (63.93%), with 21 (34.43%) in the right upper lung. And the left lung was involved in 22 (36.07%), with 15 (24.59%) in the left upper lung (Table 2 and Figure 1).\u003c/p\u003e\n\u003cp\u003eBronchoscopy identified bronchial infiltration, stenosis, occlusion, and intraluminal neoplasms in the POP group, noting bronchial occlusion in 56 cases (91.8%), intraluminal neoplasms in 57 cases (93.44%), bronchial infiltration in 24 cases (39.34) and bronchial stenosis in 5 cases (8.20%). Pathology revealed squamous cell carcinoma in 52 cases (85.25%), adenocarcinoma in 3 (4.92%), hamartoma in 2 (3.28%), carcinoid in 2 (3.28%), small cell lung cancer in 1 (1.64%), and dysplasia in 1 (1.64%) (Figure 1).\u003c/p\u003e\n\u003cp\u003eUnivariate logistic regression analysis was applied to statistically significant variables, with those showing P \u0026lt; 0.05 and OR \u0026gt; 1 progressing to multivariate analysis. This analysis identified elderly individuals, males, and CT imaging findings of bronchial obstruction, bronchial stenosis, bronchial mucus embolism, and intrabronchial shadows as independent risk factors for endobronchial tumors (P \u0026lt; 0.05) , as shown in Table 3. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe time from the first appearance of imaging abnormalities in CT to the diagnosis of endobronchial tumors through bronchoscopy is defined as the delay time. If an abnormality is reported by CT and immediate hospitalization or outpatient bronchoscopy is performed, the delay time is 0. We found that the average delay time in the POP group is 214.8 days (range: 0-1170 days). In the POP group, 34 patients (55.74%) had abnormal CT images in the past and did not undergo bronchoscopy, resulting in delayed diagnosis. Thus, prompt recognition of specified imaging characteristics is vital to reduce diagnostic delays. In the post-obstructive pneumonia group, bronchial occlusion imaging showed high sensitivity (65.5%) and specificity (92.2%). Sensitivity increased to 96.7% when combined with bronchial stenosis, but no significant enhancement was noted with other imaging features(Table 4).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCase presentation\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA 68-year-old male experienced intermittent cough and fever for the past five days. Physical examination identified diminished breath sounds in the right lower lung. A chest CT on July 20, 2022, depicted a right hilar mass, right lower lobe atelectasis, nodules in the right main trachea and bronchus, and right lower lung inflammation (Fig. 2A). A bronchoscopy conducted on July 26, 2022, revealed a smooth neoplasm at the lower lobe bronchus ostium of the right lung (Fig. 2B), diagnosed as squamous cell carcinoma through pathological examination (Fig. 2C). The patient underwent surgical intervention. A retrospective review of a chest CT from October 20, 2020, at a different facility showed narrowing at the right lower bronchial ostium (Fig. 2D), indicating a diagnostic delay of 644 days for this patient.\u003c/p\u003e\n\u003cp\u003eTable 1.\u0026nbsp;Comparison of patient data between the POP group and the CAP\u0026nbsp;group\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eCharacteristic\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003ePOP group (n=61)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003eCAP group (n=102)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eP\u0026nbsp;\u003c/em\u003eValue\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eDemographics and comorbidities\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eAge, y\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e69(58-80)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e59(38-80)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eBody mass index, kg/m2\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e21.58\u0026plusmn;2.45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e22.11\u0026plusmn;3.27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e0.282\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eMale sex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e57(93.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e48(47.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eSmoking\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e41(67.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e15(14.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eComorbidities\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e30(49.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e60(58.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e0.257\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eClinical features\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eCough\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e52(85.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e94(92.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e0.190\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eSputum\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e42(68.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e85(83.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.034\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eHemoptysis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e16(26.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e11(10.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.016\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eChest pain\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e14(23.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e12(11.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.049\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eDyspnea\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e9(14.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e15(14.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e1.000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eWheezing\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e5(8.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e9(8.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e1.000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eTemperature \u0026gt;37.4\u0026deg;C\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e9(14.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e47(46.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eLaboratory features\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eC-reactive protein, mg/L\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e8.35(5.00-102.86)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e36.96(5.54-94.63)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e0.228\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eProcalcitonin, \u0026nbsp;ng/mL\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e0.25(0.09-0.25)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e0.25(0.05-0.25)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.013\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eWhite blood cell count, cells/\u0026micro;L\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e7.93(5.62-9.03)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e7(5.42-9.79)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e0.325\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eLymphocyte count, cells/\u0026micro;L\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e1.34(1.11-1.94)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e1.4(1.15-1.78)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e0.715\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eNeutrophil Count, cells/\u0026micro;L\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e5.65(3.72-6.79)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e4.54(3.09-7.22)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e0.469\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003ePlatelet count, cells/\u0026micro;L\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e228.5(196.50-315.75)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e263(196-319)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e0.907\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eGlobular value, g/L\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e128.5(117.5-139.25)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e126(112-135)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e0.075\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eCEA, \u0026nbsp;ng/mL\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e2.73(2.03-4.62)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e1.67(1.23-2.42)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eSCC, \u0026nbsp;ng/mL\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e1.59(1.91)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e1.04(0.78-1.41)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eCYFRA21-1, \u0026nbsp;ng/mL\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e4.06(2.56-6.04)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e1.98(1.55-2.89)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eNSE, \u0026nbsp;ng/mL\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e12.90(10.21-17.27)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e13(10.91-15.19)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e0.853\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eRadiographic features\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eConsolidation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e7(11.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e46(45.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eExudation\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e30(49.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e90(88.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eEmphysema\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e8(13.11)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e1(1.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.002\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eBronchial wall thickening\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e12(19.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e2(2.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eBronchial occlusion\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e40(65.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e8(7.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003ch3\u003eBronchial-stenosis\u003c/h3\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e32(52.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e16(15.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eAtelectasis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e7(11.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e7(6.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e0.388\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eBronchial mucus embolism\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e19(31.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e3(2.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eShadow in the lumen of the bronchi\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e29(47.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e8(7.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003ePleural effusion\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e2(3.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e10(9.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e0.213\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"35.95706618962433%\" valign=\"top\"\u003e\n \u003cp\u003eLymphadenectasis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e15(24.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.329159212880143%\" valign=\"top\"\u003e\n \u003cp\u003e34(33.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.384615384615385%\" valign=\"top\"\u003e\n \u003cp\u003e0.291\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eData are shown as No. (%) of patients and refer to values at the time of admission, unless stated otherwise.\u003c/p\u003e\n\u003cp\u003eAbbreviations: CEA, carcinoembryonic antigen; SCC, squamous cell carcinoma antigen;\u0026nbsp;CYFRA21-1, cytokeratin 19 fragment; NSE, neuron-specific enolase.\u003c/p\u003e\n\u003cp\u003e\u003csup\u003ea\u0026nbsp;\u003c/sup\u003eMedian (interquartile range).\u003c/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003cp\u003eTable 2.\u0026nbsp;Bronchoscopic findings in the\u0026nbsp;POP group\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"66.19718309859155%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eSite\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.80281690140845%\" valign=\"top\"\u003e\n \u003cp\u003ePOP group (n=61)\u0026nbsp;(n，%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.704225352112676%\" rowspan=\"3\"\u003e\n \u003cp\u003eRight upper lobe\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"40.49295774647887%\" valign=\"top\"\u003e\n \u003cp\u003eAnterior segment\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.80281690140845%\" valign=\"top\"\u003e\n \u003cp\u003e8，13.11%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"54.502369668246445%\" valign=\"top\"\u003e\n \u003cp\u003eApical segment\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"45.497630331753555%\" valign=\"top\"\u003e\n \u003cp\u003e6，9.84%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"54.502369668246445%\" valign=\"top\"\u003e\n \u003cp\u003ePosterior segment\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"45.497630331753555%\" valign=\"top\"\u003e\n \u003cp\u003e7，11.48%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.704225352112676%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"40.49295774647887%\" valign=\"top\"\u003e\n \u003cp\u003eRight middle lobar bronchus\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.80281690140845%\" valign=\"top\"\u003e\n \u003cp\u003e1，1.64%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.704225352112676%\" rowspan=\"2\"\u003e\n \u003cp\u003eRight inferior lobe\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"40.49295774647887%\" valign=\"top\"\u003e\n \u003cp\u003eDorsal segment\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.80281690140845%\" valign=\"top\"\u003e\n \u003cp\u003e8，13.11%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"54.502369668246445%\" valign=\"top\"\u003e\n \u003cp\u003eBasal segment\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"45.497630331753555%\" valign=\"top\"\u003e\n \u003cp\u003e9，14.75%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.704225352112676%\" rowspan=\"2\"\u003e\n \u003cp\u003eLeft\u0026nbsp;upper lobe\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"40.49295774647887%\" valign=\"top\"\u003e\n \u003cp\u003eAnterior segment\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.80281690140845%\" valign=\"top\"\u003e\n \u003cp\u003e8，13.11%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"54.502369668246445%\" valign=\"top\"\u003e\n \u003cp\u003eIntrinsic \u0026nbsp;bronchus\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"45.497630331753555%\" valign=\"top\"\u003e\n \u003cp\u003e6，9.83%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.704225352112676%\"\u003e\n \u003cp\u003eLeft\u0026nbsp;upper lobe\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"40.49295774647887%\" valign=\"top\"\u003e\n \u003cp\u003eLingular bronchi\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.80281690140845%\" valign=\"top\"\u003e\n \u003cp\u003e1，1.64%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.704225352112676%\" rowspan=\"2\"\u003e\n \u003cp\u003e\u0026nbsp;Left inferior lobe\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"40.49295774647887%\" valign=\"top\"\u003e\n \u003cp\u003eBasal segment\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.80281690140845%\" valign=\"top\"\u003e\n \u003cp\u003e5，8.20%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"54.502369668246445%\" valign=\"top\"\u003e\n \u003cp\u003eDorsal segment\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"45.497630331753555%\" valign=\"top\"\u003e\n \u003cp\u003e2，3.28%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003cp\u003eTable 3. Risk factors of endobronchial tumor complicated with POP\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"18.117229129662523%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.78152753108348%\" valign=\"top\"\u003e\n \u003cp\u003eIndex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.742451154529308%\" valign=\"top\"\u003e\n \u003cp\u003eSingle factor OR\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.2753108348135%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eP\u0026nbsp;\u003c/em\u003eValue\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.761989342806395%\" valign=\"top\"\u003e\n \u003cp\u003eMultiple factor OR\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.321492007104796%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eP\u0026nbsp;\u003c/em\u003eValue\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"18.117229129662523%\" rowspan=\"3\"\u003e\n \u003cp\u003eDemographics\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.78152753108348%\" valign=\"top\"\u003e\n \u003cp\u003eGender\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.742451154529308%\" valign=\"top\"\u003e\n \u003cp\u003e16.03\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.2753108348135%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;\u003c/strong\u003e0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.761989342806395%\" valign=\"top\"\u003e\n \u003cp\u003e12.335\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.321492007104796%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.014\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.379609544468547%\" valign=\"top\"\u003e\n \u003cp\u003eAge\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.004338394793926%\" valign=\"top\"\u003e\n \u003cp\u003e1.088\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.655097613882862%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;\u003c/strong\u003e0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.691973969631235%\" valign=\"top\"\u003e\n \u003cp\u003e1.289\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.268980477223426%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.011\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.379609544468547%\" valign=\"top\"\u003e\n \u003cp\u003eSmoking history\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.004338394793926%\" valign=\"top\"\u003e\n \u003cp\u003e1.078\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.655097613882862%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;\u003c/strong\u003e0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.691973969631235%\" valign=\"top\"\u003e\n \u003cp\u003e1.034\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.268980477223426%\" valign=\"top\"\u003e\n \u003cp\u003e0.072\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"18.117229129662523%\" rowspan=\"4\"\u003e\n \u003cp\u003eLaboratory features\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.78152753108348%\" valign=\"top\"\u003e\n \u003cp\u003ePCT\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.742451154529308%\" valign=\"top\"\u003e\n \u003cp\u003e2.386\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.2753108348135%\" valign=\"top\"\u003e\n \u003cp\u003e0.132\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.761989342806395%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.321492007104796%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.379609544468547%\" valign=\"top\"\u003e\n \u003cp\u003eCEA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.004338394793926%\" valign=\"top\"\u003e\n \u003cp\u003e1.925\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.655097613882862%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;\u003c/strong\u003e0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.691973969631235%\" valign=\"top\"\u003e\n \u003cp\u003e1.195\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.268980477223426%\" valign=\"top\"\u003e\n \u003cp\u003e0.495\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.379609544468547%\" valign=\"top\"\u003e\n \u003cp\u003eSCC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.004338394793926%\" valign=\"top\"\u003e\n \u003cp\u003e1.425\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.655097613882862%\" valign=\"top\"\u003e\n \u003cp\u003e0.011\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.691973969631235%\" valign=\"top\"\u003e\n \u003cp\u003e1.034\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.268980477223426%\" valign=\"top\"\u003e\n \u003cp\u003e0.904\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.379609544468547%\" valign=\"top\"\u003e\n \u003cp\u003eCYFRA21-1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.004338394793926%\" valign=\"top\"\u003e\n \u003cp\u003e1.426\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.655097613882862%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;\u003c/strong\u003e0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.691973969631235%\" valign=\"top\"\u003e\n \u003cp\u003e1.248\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.268980477223426%\" valign=\"top\"\u003e\n \u003cp\u003e0.181\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"18.117229129662523%\" rowspan=\"8\"\u003e\n \u003cp\u003eRadiographic features\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.78152753108348%\" valign=\"top\"\u003e\n \u003cp\u003eConsolidation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.742451154529308%\" valign=\"top\"\u003e\n \u003cp\u003e0.158\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.2753108348135%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;\u003c/strong\u003e0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.761989342806395%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.321492007104796%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.379609544468547%\" valign=\"top\"\u003e\n \u003cp\u003eExudation\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.004338394793926%\" valign=\"top\"\u003e\n \u003cp\u003e0.129\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.655097613882862%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;\u003c/strong\u003e0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.691973969631235%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.268980477223426%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.379609544468547%\" valign=\"top\"\u003e\n \u003cp\u003eEmphysema\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.004338394793926%\" valign=\"top\"\u003e\n \u003cp\u003e15.245\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.655097613882862%\" valign=\"top\"\u003e\n \u003cp\u003e0.011\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.691973969631235%\" valign=\"top\"\u003e\n \u003cp\u003e14.253\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.268980477223426%\" valign=\"top\"\u003e\n \u003cp\u003e0.065\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.379609544468547%\" valign=\"top\"\u003e\n \u003cp\u003eBronchial wall thickening\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.004338394793926%\" valign=\"top\"\u003e\n \u003cp\u003e12.245\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.655097613882862%\" valign=\"top\"\u003e\n \u003cp\u003e0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.691973969631235%\" valign=\"top\"\u003e\n \u003cp\u003e5.283\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.268980477223426%\" valign=\"top\"\u003e\n \u003cp\u003e0.167\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.379609544468547%\" valign=\"top\"\u003e\n \u003cp\u003eBronchial occlusion\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.004338394793926%\" valign=\"top\"\u003e\n \u003cp\u003e22.381\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.655097613882862%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;\u003c/strong\u003e0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.691973969631235%\" valign=\"top\"\u003e\n \u003cp\u003e61.349\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.268980477223426%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.379609544468547%\" valign=\"top\"\u003e\n \u003ch3\u003eBronchial stenosis\u003c/h3\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.004338394793926%\" valign=\"top\"\u003e\n \u003cp\u003e5.931\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.655097613882862%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;\u003c/strong\u003e0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.691973969631235%\" valign=\"top\"\u003e\n \u003cp\u003e11.032\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.268980477223426%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.379609544468547%\" valign=\"top\"\u003e\n \u003cp\u003eBronchial mucus embolism\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.004338394793926%\" valign=\"top\"\u003e\n \u003cp\u003e14.929\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.655097613882862%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;\u003c/strong\u003e0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.691973969631235%\" valign=\"top\"\u003e\n \u003cp\u003e20.858\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.268980477223426%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.013\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.379609544468547%\" valign=\"top\"\u003e\n \u003cp\u003eShadow in the lumen of the bronchi\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.004338394793926%\" valign=\"top\"\u003e\n \u003cp\u003e10.648\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.655097613882862%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;\u003c/strong\u003e0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.691973969631235%\" valign=\"top\"\u003e\n \u003cp\u003e5.758\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.268980477223426%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.038\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTable 4.\u0026nbsp;Diagnostic value of single and combined imaging findings in endobronchial tumor\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"44.28822495606327%\" valign=\"top\"\u003e\n \u003cp\u003eRadiographic features\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.75043936731107%\" valign=\"top\"\u003e\n \u003cp\u003eSensitivity\u0026nbsp;(%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.520210896309315%\" valign=\"top\"\u003e\n \u003cp\u003eSpecificity(%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.441124780316343%\" valign=\"top\"\u003e\n \u003cp\u003eJorden index\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"44.28822495606327%\" valign=\"top\"\u003e\n \u003cp\u003eBronchial occlusion\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.75043936731107%\" valign=\"top\"\u003e\n \u003cp\u003e65.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.520210896309315%\" valign=\"top\"\u003e\n \u003cp\u003e92.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.441124780316343%\" valign=\"top\"\u003e\n \u003cp\u003e0.577\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"44.28822495606327%\" valign=\"top\"\u003e\n \u003cp\u003eBronchial-stenosis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.75043936731107%\" valign=\"top\"\u003e\n \u003cp\u003e52.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.520210896309315%\" valign=\"top\"\u003e\n \u003cp\u003e84.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.441124780316343%\" valign=\"top\"\u003e\n \u003cp\u003e0.368\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"44.28822495606327%\" valign=\"top\"\u003e\n \u003cp\u003eBronchial mucus embolism\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.75043936731107%\" valign=\"top\"\u003e\n \u003cp\u003e31.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.520210896309315%\" valign=\"top\"\u003e\n \u003cp\u003e97.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.441124780316343%\" valign=\"top\"\u003e\n \u003cp\u003e0.282\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"44.28822495606327%\" valign=\"top\"\u003e\n \u003cp\u003eShadow in the lumen of the bronchi\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.75043936731107%\" valign=\"top\"\u003e\n \u003cp\u003e47.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.520210896309315%\" valign=\"top\"\u003e\n \u003cp\u003e92.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.441124780316343%\" valign=\"top\"\u003e\n \u003cp\u003e0.397\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"44.28822495606327%\" valign=\"top\"\u003e\n \u003cp\u003eOcclusion/Stenosis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.75043936731107%\" valign=\"top\"\u003e\n \u003cp\u003e96.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.520210896309315%\" valign=\"top\"\u003e\n \u003cp\u003e78.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.441124780316343%\" valign=\"top\"\u003e\n \u003cp\u003e0.751\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"44.28822495606327%\" valign=\"top\"\u003e\n \u003cp\u003eOcclusion//Shadow in the lumen\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.75043936731107%\" valign=\"top\"\u003e\n \u003cp\u003e73.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.520210896309315%\" valign=\"top\"\u003e\n \u003cp\u003e79.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.441124780316343%\" valign=\"top\"\u003e\n \u003cp\u003e0.532\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"44.28822495606327%\" valign=\"top\"\u003e\n \u003cp\u003eOcclusion/Shadow in the lumen\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.75043936731107%\" valign=\"top\"\u003e\n \u003cp\u003e82.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.520210896309315%\" valign=\"top\"\u003e\n \u003cp\u003e88.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.441124780316343%\" valign=\"top\"\u003e\n \u003cp\u003e0.702\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"44.28822495606327%\" valign=\"top\"\u003e\n \u003cp\u003eSstenosis/Occlusion/Shadow in the lumen\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.75043936731107%\" valign=\"top\"\u003e\n \u003cp\u003e98.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.520210896309315%\" valign=\"top\"\u003e\n \u003cp\u003e77.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.441124780316343%\" valign=\"top\"\u003e\n \u003cp\u003e0.759\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"44.28822495606327%\" valign=\"top\"\u003e\n \u003cp\u003eStenosis/Occlusion/Bronchial mucus embolism\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.75043936731107%\" valign=\"top\"\u003e\n \u003cp\u003e98.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.520210896309315%\" valign=\"top\"\u003e\n \u003cp\u003e78.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.441124780316343%\" valign=\"top\"\u003e\n \u003cp\u003e0.768\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"44.28822495606327%\" valign=\"top\"\u003e\n \u003cp\u003eStenosis/Occlusion/Shadow in the lumen/Bronchial mucus embolism\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.75043936731107%\" valign=\"top\"\u003e\n \u003cp\u003e98.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.520210896309315%\" valign=\"top\"\u003e\n \u003cp\u003e77.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.441124780316343%\" valign=\"top\"\u003e\n \u003cp\u003e0.759\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e"},{"header":"Discussion","content":"\u003cp\u003eAccording to the WHO International Agency for Research on Cancer, lung cancer is the leading cause of cancer-related morbidity and mortality worldwide [5]. This is largely due to 85% of patients being diagnosed at advanced stages, missing early diagnostic and treatment opportunities [6]. Lung cancer primarily affects older men, with smoking as the foremost risk factor, although the influence of other factors like environmental pollution and exposure to radioactive substances is on the rise [7].\u003c/p\u003e\n\u003cp\u003eEndobronchial lesions are potential precursors to central airway lung carcinomas. Early identification and treatment of these lesions can prevent their progression to invasive carcinoma. Of the 61 patients with obstructive pneumonia and endobronchial tumors, 57 were male, and 41 had a smoking history. Univariate analysis identified gender and smoking as independent risk factors for endobronchial tumors, aligning with prior research. While quitting smoking reduces lung cancer risk, former smokers still face a risk nine times greater than non-smokers [8]. Chiaki Endo et al. [9] analyzed 251 patients with early-stage central airway lung cancer, 207 of whom underwent surgical resection. They reported 5-year and 10-year survival rates post-treatment of 96.7% and 94.9%, respectively. Early diagnosis and thorough resection of central pneumonia are crucial for enhancing lung cancer survival rates [10].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eMSCT is essential in assessing endobronchial lesions, providing valuable information on tracheal stenosis, bronchial wall thickening, obstruction, tracheobronchial malacia, and both benign and malignant bronchial tumors. Its application in screening high-risk individuals significantly lowers the relative risk of dying from lung cancer [11]. Guidelines recommend MSCT for early diagnosis and screening in high-risk groups [12]. Nonetheless, MSCT may overlook endobronchial lesions, highlighting the need for integrating characteristic imaging features with bronchoscopy to ensure early lesion detection.\u003c/p\u003e\n\u003cp\u003eTumor growth within the bronchial lumen can lead to irregular stenosis, thickening, and occlusion of the bronchial wall, manifesting as indirect imaging signs like obstructive pneumonia, emphysema, and atelectasis. Yet, clinicians often misinterpret post-obstructive pneumonia as community-acquired pneumonia, resulting in missed early diagnostic and treatment opportunities for endobronchial tumors. Unlike community-acquired pneumonia, post-obstructive pneumonia stems from bronchial obstruction, causing impaired drainage of distal secretions or atelectasis, sometimes with a secondary infection. The term \u0026quot;postobstructive pneumonia\u0026quot; was coined in the 1970s, replacing \u0026quot;obstructive pneumonitis\u0026quot;[13]. McDonald et al. [14] characterized radiographic opacity from bronchial obstruction by a tumor as post-obstructive pneumonitis. Although research on obstructive pneumonia is limited, evidence suggests many patients initially diagnosed with community-acquired pneumonia actually have underlying lung cancer[15,16]. Early detection hinges on understanding normal bronchial anatomy, comparing bilateral pulmonary bronchi, and utilizing advanced imaging techniques. Prompt bronchoscopy and biopsy are pivotal for enhancing early diagnosis rates. Certain rare tumors, like lung carcinoids, typically necessitate bronchoscopy for accurate diagnosis due to the limitations of imaging techniques such as CT or PET/CT[17]. Misidentifying intraluminal bronchial tumors and obstructive pneumonia can worsen endobronchial obstruction, increasing the risk of recurrent pulmonary infections, tumor progression, and higher mortality rates. Post-obstructive pneumonia patients often endure longer symptom durations and higher mortality than those with community-acquired pneumonia[18]. While community-acquired pneumonia imaging typically shows consolidation and exudation, obstructive pneumonia features distinct signs like bronchial wall thickening, occlusion, stenosis, obstructive emphysema, bronchial mucus embolism, and intraluminal shadows. Significantly, bronchial occlusion is highly specific for tumor screening, with imaging of bronchial stenosis and/or occlusion aligning closely with bronchoscopic findings for high sensitivity.\u003c/p\u003e\n\u003cp\u003eEndobronchial tumors include both benign and malignant types, with the latter encompassing squamous cell carcinoma, adenocarcinoma, carcinoid, adenoid cystic carcinoma, and metastatic tumors. Benign varieties consist of hamartomas, neurogenic tumors, and lipomas[19,20]. Endobronchial resection is often the preferred method for diagnosing and treating these tumors.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn our study, bronchial occlusion and neoplasms were the predominant bronchoscopic findings in patients with post-obstructive pneumonia, representing a significant portion of the cases. Squamous cell carcinoma emerged as the leading pathological type among these lesions, highlighting the necessity of early detection of imaging signs indicative of squamous cell carcinoma. Notably, post-obstructive pneumonia seems to occur more frequently in patients with squamous cell carcinoma than in those with adenocarcinoma, aligning with previous research findings.\u003c/p\u003e\n\u003cp\u003eHowever, this study has several limitations. First, it is a single-center study conducted at Affiliated Yueqing Hospital of Wenzhou Medical University, potentially limiting the generalizability of the results to other centers or populations. Furthermore, its retrospective nature means it relies on historical data, which may impact the accuracy of the findings.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn conclusion, There is a possibility of misdiagnosis as community-acquired pneumonia when endobronchial tumors associated with post-obstructive pneumonia. Factors like bronchial occlusion, stenosis, mucus embolism, and intraluminal shadows on CT are significant independent risk factors for endobronchial tumors. Clinicians and radiologists should be vigilant for bronchial abnormalities in pneumonia patients on imaging, particularly when antibiotic treatment is ineffective, and undergo bronchoscopy as early as possible to determine endobronchial tumors.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe wish to acknowledge all the participants, medical-, nursing-, and technical-staff who has been involved in collecting the samples for this study.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eW.\u0026nbsp;Y., Y.\u0026nbsp;L., Y.\u0026nbsp;S.\u0026nbsp;performed the research, collected and analyzed the data and wrote the\u0026nbsp;paper.\u0026nbsp;X.Z.,\u0026nbsp;A.C.,\u0026nbsp;Z.\u0026nbsp;Y., and\u0026nbsp;W.Z. contributed to sample collection.\u0026nbsp;Q.\u0026nbsp;Z.\u0026nbsp;, J.\u0026nbsp;C.\u0026nbsp;,\u0026nbsp;L.\u0026nbsp;Z.and\u0026nbsp;H.Y.,\u0026nbsp;L.L.contributed\u0026nbsp;to supervision of this study and revision of the manuscript. All authors\u0026nbsp;reviewed the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study has not been funded.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data that support the fndings of this study are available from the corresponding author upon reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe present study was conducted in accordance with the amended\u0026nbsp;Declaration of Helsinki. The Ethics Committee of Affiliated Yueqing Hospital of Wenzhou Medical University approved the protocol of this retrospective study (approval number: YQYY202300206), and granting a waiver of informed consent due to the retrospective nature of data collection.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to publish\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eTorres A, Ferrer M. \u003cstrong\u003eEditorial Commentary: Distinguishing Postobstructive Lung Infection From Community-Acquired Pneumonia\u003c/strong\u003e[J]. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America 2016, 62(8):962-963.\u003c/li\u003e\n\u003cli\u003eMoretti M, Wellekens S, Dirkx S, et al. \u003cstrong\u003eFeatures of post-obstructive pneumonia in advanced lung cancer patients, a large retrospective cohort\u003c/strong\u003e[J]. Infectious diseases (London, England) 2023, 55(2):149-157.\u003c/li\u003e\n\u003cli\u003eRolston KVI, Nesher L. \u003cstrong\u003ePost-Obstructive Pneumonia in Patients with Cancer: A Review\u003c/strong\u003e[J]. Infectious diseases and therapy 2018, 7(1):29-38.\u003c/li\u003e\n\u003cli\u003eLiu YH, Wu LL, Qian JY, et al. \u003cstrong\u003eA Nomogram Based on Atelectasis/Obstructive Pneumonitis Could Predict the Metastasis of Lymph Nodes and Postoperative Survival of Pathological N0 Classification in Non-small Cell Lung Cancer Patients\u003c/strong\u003e[J]. Biomedicines 2023, 11(2).\u003c/li\u003e\n\u003cli\u003eSung H, Ferlay J, Siegel RL, et al. \u003cstrong\u003eGlobal Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries\u003c/strong\u003e[J]. CA: a cancer journal for clinicians 2021, 71(3):209-249.\u003c/li\u003e\n\u003cli\u003eMattiuzzi C, Lippi G. \u003cstrong\u003eCurrent Cancer Epidemiology\u003c/strong\u003e[J]. Journal of epidemiology and global health 2019, 9(4):217-222.\u003c/li\u003e\n\u003cli\u003eBade BC, Dela Cruz CS. \u003cstrong\u003eLung Cancer 2020: Epidemiology, Etiology, and Prevention\u003c/strong\u003e[J]. Clinics in chest medicine 2020, 41(1):1-24.\u003c/li\u003e\n\u003cli\u003eWood DE, Kazerooni EA, Baum SL, et al. \u003cstrong\u003eLung Cancer Screening, Version 3.2018, NCCN Clinical Practice Guidelines in Oncology\u003c/strong\u003e[J]. Journal of the National Comprehensive Cancer Network : JNCCN 2018, 16(4):412-441.\u003c/li\u003e\n\u003cli\u003eEndo C, Sakurada A, Kondo T. \u003cstrong\u003eEarly central airways lung cancer\u003c/strong\u003e[J]. General thoracic and cardiovascular surgery 2012, 60(9):557-560.\u003c/li\u003e\n\u003cli\u003eYotsukura M, Asamura H, Motoi N, et al. \u003cstrong\u003eLong-Term Prognosis of Patients With Resected Adenocarcinoma In Situ and Minimally Invasive Adenocarcinoma of the Lung\u003c/strong\u003e[J]. Journal of thoracic oncology : official publication of the International Association for the Study of Lung Cancer 2021, 16(8):1312-1320.\u003c/li\u003e\n\u003cli\u003eHorst C, Nair A, Janes SM. \u003cstrong\u003eLessons on managing pulmonary nodules from NELSON: we have come a long way\u003c/strong\u003e[J]. Thorax 2019, 74(5):427-429.\u003c/li\u003e\n\u003cli\u003eShen H. \u003cstrong\u003eLow-dose CT for lung cancer screening: opportunities and challenges\u003c/strong\u003e[J]. Frontiers of medicine 2018, 12(1):116-121.\u003c/li\u003e\n\u003cli\u003eCohen AB, Cline MJ. \u003cstrong\u003eThe human alveolar macrophage: isolation, cultivation in vitro, and studies of morphologic and functional characteristics\u003c/strong\u003e[J]. The Journal of clinical investigation 1971, 50(7):1390-1398.\u003c/li\u003e\n\u003cli\u003eMc DJ, Harrington SW, Clagett OT. \u003cstrong\u003eObstructive pneumonitis of neoplastic origin; an interpretation of one form of so-called atelectasis and its correlation according to presence of absence of sputum\u003c/strong\u003e[J]. The Journal of thoracic surgery 1949, 18(1):97-112; disc., 122.\u003c/li\u003e\n\u003cli\u003eMarrie TJ. \u003cstrong\u003ePneumonia and carcinoma of the lung\u003c/strong\u003e[J]. The Journal of infection 1994, 29(1):45-52.\u003c/li\u003e\n\u003cli\u003eMusher DM, Roig IL, Cazares G, et al. \u003cstrong\u003eCan an etiologic agent be identified in adults who are hospitalized for community-acquired pneumonia: results of a one-year study\u003c/strong\u003e[J]. The Journal of infection 2013, 67(1):11-18.\u003c/li\u003e\n\u003cli\u003eMu R, Meng Z, Guo Z, et al. \u003cstrong\u003eDiagnostic value of dual-layer spectral detector CT in differentiating lung adenocarcinoma from squamous cell carcinoma\u003c/strong\u003e[J]. Frontiers in oncology 2022, 12:868216.\u003c/li\u003e\n\u003cli\u003eAbers MS, Sandvall BP, Sampath R, et al. \u003cstrong\u003ePostobstructive Pneumonia: An Underdescribed Syndrome\u003c/strong\u003e[J]. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America 2016, 62(8):957-961.\u003c/li\u003e\n\u003cli\u003eStevic R, Milenkovic B. \u003cstrong\u003eTracheobronchial tumors\u003c/strong\u003e[J]. Journal of thoracic disease 2016, 8(11):3401-3413.\u003c/li\u003e\n\u003cli\u003eInsler JE, Seder CW, Furlan K, et al. \u003cstrong\u003eBenign Endobronchial Tumors: A Clinicopathologic Review\u003c/strong\u003e[J]. Frontiers in surgery 2021, 8:644656.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-pulmonary-medicine","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"pulm","sideBox":"Learn more about [BMC Pulmonary Medicine](http://bmcpulmmed.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/pulm/default.aspx","title":"BMC Pulmonary Medicine","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Post-obstructive pneumonia, Community acquired pneumonia, Endobronchial tumor","lastPublishedDoi":"10.21203/rs.3.rs-4705907/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4705907/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground \u003c/strong\u003eEndobronchial tumors can infiltrate the bronchial wall or protrude into the bronchial lumen, causing post-obstructive pneumonia (POP). Differentiating between POP and community-acquired pneumonia (CAP) is challenging due to similar clinical, laboratory, and imaging findings, which can delay the diagnosis and treatment of endobronchial tumors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e We compared general demographic information, laboratory test results, lung CT images, bronchoscopic observations, pathological findings between the POP group and the CAP group.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e 1. The POP group consisted mainly of older individuals (mean age 69 vs. 56 years; P \u0026lt; 0.05), males (93.4% vs. 47.1%; P \u0026lt; 0.05), and smokers (67.2% vs. 14.7%; P \u0026lt; 0.05). Clinical symptoms varied, with chest pain (23.0% vs. 11.8%; P \u0026lt; 0.05) and hemoptysis (26.2% vs. 10.8%; P \u0026lt; 0.05) more prevalent in the POP group. MSCT showed that bronchial wall thickening, bronchial stenosis, occlusion, obstructive emphysema, mucoid impaction, and endobronchial shadows occurred more frequently in POP, while consolidation and exudation shadows were predominant in CAP (P \u0026lt; 0.05). 2. In the POP group, neoplasms were the most frequent bronchoscopic findings (57 cases, 93.44%), especially in the upper lungs. Squamous cell carcinoma was the primary pathological type (52 cases, 85.25%). The average delay in diagnosing endobronchial tumors was 214.8 days. In the POP group, 34 cases (55.74%) had abnormal CT images in the past and did not undergo bronchoscopy, resulting in delayed diagnosis. 3. Factors such as gender, age, bronchial occlusion, stenosis, mucus embolism, and intraluminal shadow were determined to be independent risk factors for endobronchial tumors (P \u0026lt; 0.05 and OR \u0026gt; 1).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions\u003c/strong\u003e Endobronchial tumors combined with POP are easily misdiagnosed as CAP in the early stage. Factors like bronchial occlusion, stenosis, mucus embolism, and intraluminal shadows on MSCT are significant independent risk factors for these tumors, indicating the need for early bronchoscopy.\u003c/p\u003e","manuscriptTitle":"Comparison between Community-Acquired Pneumonia and Post-Obstructive Pneumonia Associated with Endobronchial Tumors","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-08-16 21:26:07","doi":"10.21203/rs.3.rs-4705907/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-07-17T12:15:20+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-07-16T12:01:12+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-07-16T12:00:52+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Pulmonary Medicine","date":"2024-07-08T13:27:43+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-pulmonary-medicine","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"pulm","sideBox":"Learn more about [BMC Pulmonary Medicine](http://bmcpulmmed.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/pulm/default.aspx","title":"BMC Pulmonary Medicine","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"74ae9bc9-343a-462c-82da-e3ed8438b5f3","owner":[],"postedDate":"August 16th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2024-12-02T17:29:07+00:00","versionOfRecord":{"articleIdentity":"rs-4705907","link":"https://doi.org/10.1186/s12890-024-03409-8","journal":{"identity":"bmc-pulmonary-medicine","isVorOnly":false,"title":"BMC Pulmonary Medicine"},"publishedOn":"2024-11-28 15:58:08","publishedOnDateReadable":"November 28th, 2024"},"versionCreatedAt":"2024-08-16 21:26:07","video":"","vorDoi":"10.1186/s12890-024-03409-8","vorDoiUrl":"https://doi.org/10.1186/s12890-024-03409-8","workflowStages":[]},"version":"v1","identity":"rs-4705907","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4705907","identity":"rs-4705907","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}