Clinical and radiological presentations of pulmonary hydatid cysts in Yemen: a retrospective cross-sectional study at a tertiary center

Clinical and radiological presentations of pulmonary hydatid cysts in Yemen: a retrospective cross-sectional study at a tertiary center | 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 Clinical and radiological presentations of pulmonary hydatid cysts in Yemen: a retrospective cross-sectional study at a tertiary center Mohammed M. Al-Shehari, Yasser Abdurabo Obadiel, Mugahed Esmail Nahshal, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9248949/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 17 You are reading this latest preprint version Abstract Background: Pulmonary hydatid cysts caused by Echinococcus granulosus represent a significant health burden in endemic regions such as Yemen. Limited contemporary data are available on the clinical and radiological characteristics of this disease in the Yemeni population. This study aimed to evaluate the clinical presentation, radiological features, surgical management, and early outcomes of pulmonary hydatid cysts at a tertiary center in Sana'a, Yemen. Methods: This retrospective cross-sectional study was conducted at Al-Thawra Modern General Hospital between January 2019 and March 2023. The medical records of 114 patients with surgically confirmed pulmonary hydatid cysts were analyzed. Demographic data, clinical presentations, radiological findings, surgical procedures, and early postoperative complications were collected using a structured questionnaire. Statistical analyses were performed using SPSS v. 28.0, and 95% confidence intervals were calculated for all proportions. Results: Of 114 patients, 82 (71.9%; 95% CI: 63.1%-79.4%) were male, with a predominant age group of 19-30 years (43.0%; 95% CI: 34.3%-52.2%). Most patients were from urban areas (75.4%; 95% CI: 66.8%-82.4%) and worked as laborers (35.1%) or students (33.3%). Khat chewing was reported by 50.0% (95% CI: 41.0%-59.0%) of the patients. The most common symptoms were cough (89.5%; 95% CI: 82.5%-93.9%), dyspnea (76.3%; 95% CI: 67.7%-83.2%), and chest pain (64.9%; 95% CI: 55.8%-73.1%). Radiologically, 97 patients (85.1%; 95% CI: 77.4%-90.5%) had solitary cysts, predominantly in the right lung (67.0%). Most cysts were intact (76.3%; 95% CI: 66.9%-83.6%) and ranged in size from 5 to 9.9 cm (62.8%). Capitonnage was performed in 91.2% (95% CI: 84.6%-95.2%) of the cases. Postoperative complications occurred in 7.9% (95% CI: 4.2%-14.3%) of patients, with no mortality reported. Hospital stay was less than 1 week for 75.4% (95% CI: 66.8%-82.4%) of patients. Conclusions: Pulmonary hydatid cysts in Yemen predominantly affect young urban males and present with respiratory symptoms. Solitary, intact cysts are the most common, and surgical management with capitonnage is safe and effective, with low morbidity rates when performed in specialized centers. Trial registration: Not applicable. hydatid cyst echinococcosis pulmonary Yemen cross-sectional study surgical management. Figures Figure 1 Figure 2 Figure 3 Figure 4 Background Pulmonary hydatid cysts, caused by the larval stage of Echinococcus granulosus , are among the most geographically widespread zoonotic diseases affecting humans. This disease poses significant medical, social, and economic burdens, particularly in endemic regions, and affects over one million people worldwide [1]. The parasite has the highest prevalence in parts of North Africa, Asia, South America, and Australia, with an annual human incidence exceeding 50 per 100,000 in endemic areas [2]. Yemen, located on the Arabian Peninsula, is a hyperendemic region for hydatid disease owing to its pastoral economy, close human-animal contact, and poor sanitation. The disease is particularly prevalent in rural areas, where livestock farming is the primary occupation and traditional practices facilitate parasite transmission [3]. Previous studies from Yemen have documented the widespread nature of this parasitic infection, with significant case loads reported in major governmental hospitals in Sana'a [4]. The clinical presentation of pulmonary hydatid cysts varies considerably depending on cyst size, location, and the presence of complications. While small, intact cysts may remain asymptomatic for years, larger cysts or those with complications can present with respiratory symptoms, including cough, dyspnea, chest pain, and hemoptysis [5, 6]. Radiological diagnosis, primarily via computed tomography, remains the cornerstone, revealing characteristic features such as well-defined cystic lesions with varying internal architectures [7]. Despite the recognized burden of hydatid disease in Yemen, there is a paucity of recent comprehensive data on the clinical and radiological presentation of pulmonary hydatid cysts in the Yemeni population. Most available studies are either outdated or focus on general hydatid disease rather than pulmonary manifestations. This knowledge gap hampers the development of evidence-based diagnostic and treatment guidelines tailored to the local disease context of the region. Therefore, this study aimed to evaluate the clinical and radiological presentations of pulmonary hydatid cysts at a major tertiary center in Sana'a, Yemen, over 4 years. The specific objectives included determining the sociodemographic characteristics of affected patients, documenting clinical presentations, characterizing radiological findings (including cyst number, size, location, and complications), and evaluating surgical management outcomes and early postoperative complications. Methods Study Design and Setting This retrospective descriptive cross-sectional study was conducted at the Al-Thawra Modern General Hospital (TMGH) in Sana'a, Yemen. TMGH is a tertiary referral center with a specialized thoracic surgery unit and serves as one of the primary hospitals for complex thoracic procedures in Yemen. Study Period and Population This study covered a four-year and three-month period from January 1, 2019, to March 31, 2023. The source population comprised all patients admitted to the thoracic surgery unit with a diagnosis of pulmonary hydatid cysts during the study period. Participant Selection A total of 140 patient records were initially identified in hospital databases. The inclusion criteria were as follows: (1) male or female patients aged 3-60 years, (2) patients with a clinical history and radiological findings consistent with pulmonary hydatid cysts; and (3) patients who underwent surgical intervention for pulmonary hydatid cysts. The exclusion criteria were as follows: (1) patients with recurrent hydatid lung disease, (2) patients who did not undergo surgical treatment, (3) patients with incomplete medical records, (4) patients who were unreachable for follow-up or refused to participate, and (5) records with insufficient data for analysis. After applying these criteria, 26 records were excluded: 8 for recurrent disease, 12 for incomplete data, and 6 for refusal to undergo a surgical intervention. The final study sample comprised 114 patients with complete data available for analysis (Figure 1). Data Collection Data were collected using a structured questionnaire developed based on previous studies. The questionnaire captured (1) sociodemographic characteristics (age, sex, residence, occupation, and social habits), (2) clinical presentation (symptoms and their duration), (3) radiological findings (number, size, location, and condition of cysts), (4) surgical procedures performed, and (5) early postoperative complications and duration of hospitalization. Data were extracted from hospital medical records archives. Additional information was obtained by telephone from patients using their recorded contact information, and verbal informed consent was obtained for participation. To minimize selection bias, consecutive patients who met the inclusion criteria were included during the study period. Information bias was mitigated through the use of a structured questionnaire and verification of medical records. Recall bias during telephone follow-up was minimized by using standardized questions. The retrospective design inherently carries the risk of missing data; however, only records with complete data were included to ensure analytical completeness. Variables The primary variables included patient demographics, clinical symptoms at presentation, radiological characteristics of hydatid cysts, surgical interventions performed, and postoperative outcomes. Radiological findings were categorized based on cyst number (solitary vs. multiple), anatomical location (lung side and lobe), cyst condition (intact, ruptured, infected), size, and associated complications. Statistical Analysis Data were analyzed using IBM SPSS Statistics version 28.0 (IBM Corp.. Armonk, NY, USA). Descriptive statistics are presented as frequencies and percentages for categorical variables. Ninety-five percent confidence intervals (95% CI) were calculated for all proportions using the Wilson score method with continuity correction. Multiple-response analysis was used for variables in which patients could provide multiple responses, such as clinical symptoms and radiological findings. Chi-square tests were used to examine the associations between categorical variables, with p < 0.05 considered statistically significant. Ethical Considerations Ethical approval for this study was obtained from the Ethics Committee of the Faculty of Medicine and Health Sciences, Sana’a University, Sana’ a, Yemen. Administrative approval and permission to access patient medical records were granted by the administration of Al-Thawra Modern General Hospital (TMGH). All data were anonymized to ensure patient confidentiality. As this was a retrospective study of medical records, the requirement for informed consent was waived by the Ethics Committee. AI Disclosure Statement This manuscript was prepared with the assistance of Kimi (Moonshot AI) for formatting compliance verification and Grammarly and Paperpal for language editing and grammar correction. All content was reviewed, verified, and approved by the authors, who took full responsibility for the accuracy and integrity of the work. Results Participant Characteristics The final study sample comprised 114 patients with surgically confirmed pulmonary hydatid cysts. The sociodemographic characteristics of the participants are summarized in Table 1. A marked male predominance was observed, with 82 males (71.9%; 95% CI: 63.1%-79.4%) and 32 females (28.1%; 95% CI: 19.9%-36.9%). The largest age group was 19-30 years (n=49, 43.0%; 95% CI: 34.3%-52.2%). Contrary to initial assumptions, most patients resided in urban areas (n=86, 75.4%; 95% CI: 66.8%-82.4%) rather than rural areas (n=28, 24.6%; 95% CI: 17.6%-33.2%). Occupation analysis revealed that 35.1% (95% CI: 26.9%-44.2%) were workers or laborers, 33.3% (95% CI: 25.3%-42.4%) were students, and 21.9% (95% CI: 15.3%-30.4%) were housewives. A history of khat chewing was reported by 57 patients (50.0%; 95% CI: 41.0%-59.0%). Table 1. Sociodemographic characteristics of 114 patients with pulmonary hydatid cysts Characteristic Category n % 95% CI Gender Male 82 71.9 63.1-79.4 Female 32 28.1 19.9-36.9 Age Group (years) <3 1 0.9 0.2-4.8 3-18 31 27.2 19.9-36.0 19-30 49 43.0 34.3-52.2 31-45 23 20.2 13.8-28.5 46-60 10 8.8 4.8-15.4 Residence Urban 86 75.4 66.8-82.4 Rural 28 24.6 17.6-33.2 Occupation Workers 40 35.1 26.9-44.2 Students 38 33.3 25.3-42.4 Housewives 25 21.9 15.3-30.4 Other/Unknown 11 9.6 5.5-16.4 Khat Chewing Yes 57 50.0 41.0-59.0 No 57 50.0 41.0-59.0 Clinical Presentation The clinical findings at diagnosis are presented in Table 2. Respiratory symptoms were almost universal. The most common presenting symptom was cough, reported in 102 patients (89.5%; 95% CI: 82.5%-93.9%), followed by dyspnea (n=87, 76.3%; 95% CI: 67.7%-83.2%) and chest pain (n=74, 64.9%; 95% CI: 55.8%-73.1%). Constitutional symptoms, such as fever, were also frequent (n=62, 54.4%; 95% CI: 45.2%-63.2%). Hemoptysis was noted in 36 patients (31.6%; 95% CI: 23.8%-40.6%), and the pathognomonic sign of expectorating grape-like material was reported by 9 patients (7.9%; 95% CI: 4.2%-14.3%). Table 2. Clinical presentation of 114 patients with pulmonary hydatid cysts at diagnosis Clinical Symptom n % 95% CI Cough 102 89.5 82.5-93.9 Dyspnea 87 76.3 67.7-83.2 Chest pain 74 64.9 55.8-73.1 Fever 62 54.4 45.2-63.2 Hemoptysis 36 31.6 23.8-40.6 Loss of appetite 15 13.2 8.1-20.6 Weight loss 13 11.4 6.8-18.5 Grape-like material 9 7.9 4.2-14.3 Nausea/vomiting 3 2.6 0.9-7.5 Radiological Findings Radiological analysis revealed that the vast majority of patients (n=97, 85.1%; 95% CI: 77.4%-90.5%) presented with a solitary cyst, whereas 17 patients (14.9%; 95% CI: 9.5%-22.6%) had multiple cysts (Figure 2). The characteristics of the solitary cysts are further detailed in Table 3. A clear predilection for the right lung was observed, which contained 67.0% (95% CI: 57.2%-75.6%) of all solitary cysts, compared to 33.0% (95% CI: 24.4%-42.8%) in the left lung. Most of these cysts were intact at the time of diagnosis (n=74, 76.3%; 95% CI: 66.9%-83.6%). Among the 21 complicated solitary cysts, 21.6% (95% CI: 14.6%-30.8%) were ruptured and 2.1% (95% CI: 0.6%-7.2%) were infected. Bronchial rupture was the most common pathway (57.1%; 95% CI: 36.5%-75.5% of ruptures), followed by pleural space rupture (38.1%; 95% CI: 20.8%-59.1%). In terms of size, most solitary cysts measured between 5 and 9.9 cm in diameter (62.8%; 95% CI: 52.2%-72.3%), with giant cysts (>15 cm) being less common (9.3%; 95% CI: 4.8%-17.3%) (Figure 3). Table 3. Radiological findings of solitary pulmonary hydatid cysts (n = 97) Characteristic Category n % 95% CI Cyst Condition Intact 74 76.3 66.9-83.6 Ruptured 21 21.6 14.6-30.8 Infected 2 2.1 0.6-7.2 Side Right 65 67.0 57.2-75.6 Left 32 33.0 24.4-42.8 Rupture Site (n=21) Bronchus 12 57.1 36.5-75.5 Pleura 8 38.1 20.8-59.1 Pericardium 1 4.8 0.8-22.7 Size (n=86) 15 cm 8 9.3 4.8-17.3 In the 17 patients with multiple cysts, 36 individual cysts were identified. In contrast to solitary cases, these were predominantly located in the left lung (61.1% of cysts). Similar to the solitary cohort, most of these multiple cysts were intact (75.0%) and typically measured less than 10 cm in diameter. Concurrent extrapulmonary disease was documented in 12 patients (10.5%; 95% CI: 6.0%-17.4%), all of whom were found to have associated liver hydatid cysts in addition to their pulmonary disease (Figure 4). Surgical Management and Outcomes Conservative, lung-sparing surgery was the primary treatment. Capitonnage was performed in 104 patients (91.2%; 95% CI: 84.6%-95.2%). Simple endocystectomy with capitonnage only was performed in 39 patients (34.2%; 95% CI: 26.1%-43.3%), while 70 patients (61.4%; 95% CI: 52.2%-69.8%) required complex procedures, including additional decortication, drainage, fistula closure, or lobectomy (Table 4). Table 4. Surgical procedures performed in 114 patients with pulmonary hydatid cysts Surgical Procedure n % 95% CI Capitonnage (any) 104 91.2 84.6-95.2 Simple (Endo+Cap only) 39 34.2 26.1-43.3 Complex (+deco/drain/lobe) 70 61.4 52.2-69.8 Other/Unknown 5 4.4 1.9-9.8 The postoperative outcomes are shown in Table 5. The overall postoperative complication rate was low at 7.9% (95% CI: 4.2%-14.3%). The most frequent complication was an unexpanded (trapped) lung, which occurred in seven patients (6.1%; 95% CI: 3.0%-12.1%), followed by pneumonia in two patients (1.8%; 95% CI: 0.5%-6.2%). No postoperative mortality was observed in this study. The majority of patients (n=86, 75.4%; 95% CI: 66.8%-82.4%) had a short hospital stay of less than one week. The mean hospital stay was 6.43 ± 5.88 days (range: 3-45 days). Table 5. Postoperative outcomes in 114 patients with pulmonary hydatid cysts Outcome n % 95% CI Any Complication 9 7.9 4.2-14.3 No Complication 105 92.1 85.7-95.8 Complication Type: Trapped lung 7 6.1 3.0-12.1 Pneumonia 2 1.8 0.5-6.2 Hospital Stay: 14 days 7 6.1 3.0-12.1 Mean hospital stay: 6.43 ± 5.88 days (Range: 3-45 days). No mortality was observed. Discussion This study provides comprehensive data on pulmonary hydatid cysts from a major tertiary center in Yemen over the past four years. Our findings confirmed that the disease predominantly affects young males from urban areas and is characterized by respiratory symptoms. The radiological pattern shows a predominance of solitary, intact cysts, and surgical management demonstrates excellent outcomes with low complication rates when performed in specialized centers. The marked male predominance (71.9%) observed in our study is consistent with several regional studies but exceeds the proportions reported in some international studies. Sheikhy et al. [8] reported a 55% male predominance in Iran, whereas Abdennadher et al. [9] found a more balanced sex distribution (51.51% male) in Tunisia than in Iran. The higher male predominance in our study may reflect occupational and cultural factors specific to Yemen, where men are more likely to engage in livestock-related activities and have greater exposure to infected animals than are women. The concentration of cases in the young adult age group (19-30 years, 43.0%) aligns with findings from similar regions with endemicity. Aldahmashi et al. [10] reported an average age of 27.75 years in a multicenter study conducted in Yemen, Egypt, and Saudi Arabia, whereas Thapaliya et al. [11] reported a mean age of 31.11 years in Pakistan. This age distribution likely reflects the long incubation period of the disease and peak exposure during childhood and adolescence in endemic areas. An important finding of our analysis is that the majority of patients (75.4%) resided in urban areas. This contrasts with our initial data and previous reports from the endemic regions. This urban predominance may reflect the referral patterns to our tertiary center, with urban patients having better access to specialized health care. The high prevalence of khat chewing (50.0%) represents a unique finding that may be related to rural lifestyle and socioeconomic factors rather than a direct causal relationship with H. cystic disease. Our analysis found no significant association between khat use and any clinical symptoms ( P > 0.05). The clinical presentation in our study, dominated by cough (89.5%) and dyspnea (76.3%), is consistent with that reported in the literature for endemic regions. Sheikhy et al. [8] reported cough in 59.8% and dyspnea in 31.1% of patients, whereas Mohammad et al. [12] found cough in 44.6% of Indian patients. The higher symptom rates in our study may indicate more advanced disease at presentation, possibly due to delayed medical consultation or limited access to healthcare facilities. In contrast to Kuzucu et al. [13], who reported chest pain as the most frequent symptom, our findings align with those of Sheikhy et al. [8], where cough was the predominant presenting complaint (89.5%). The presence of hemoptysis in 31.6% of our patients is notably higher than the 12-21% range reported in most studies [14]. This finding, along with the proportion of ruptured cysts (21.6%), suggests that many patients presented with complicated disease, emphasizing the need for early diagnosis and intervention in endemic areas. The predominance of solitary cysts (85.1%) in our study is consistent with that of previous studies. Kocaman et al. [2] reported solitary cysts in the majority of their Turkish pediatric population. Simultaneously, right lung predominance (67.0%) aligns with anatomical factors related to bronchial anatomy and blood flow distribution. The size distribution, with most cysts measuring 5-9.9 cm (62.8%), suggests that patients presented with moderately sized cysts that were symptomatic but not yet at the giant cyst stage. This pattern differs from that reported in some studies, which reported higher proportions of giant cysts (>10 cm), possibly reflecting differences in healthcare access and timing of presentation [9]. The rupture rate of 21.6% for solitary cysts falls within the range of 24.7%–61% reported in the literature [15]. The predominant rupture into the bronchi (57.1%) versus the pleura (38.1%) has important clinical implications, as bronchial rupture typically presents with pathognomonic symptoms such as hydatoptysis. In contrast, pleural rupture can lead to serious complications, including empyema and pneumothorax. The high success rate of conservative surgical procedures (capitonnage in 91.2% of cases) demonstrates the effectiveness of lung-sparing techniques by experienced surgeon. This approach aligns with the current surgical philosophy, which favors parenchymal preservation whenever possible [16]. The low rate of lung resection (4.4%, including lobectomy and wedge resection) compares favorably with other series and reflects both appropriate patient selection and surgical expertise. Notably, while Abdennadher et al. [9] required anatomical resection in 45.46% of giant cyst cases, our series achieved high success with parenchyma-preserving capitonnage (91.2%), even in a cohort with significant cyst diameters. The overall complication rate of 7.9% and the absence of mortality in our series are excellent and compare favorably with the published literature reporting complication rates of up to 20% and mortality rates of 0-2% [17]. The most common complication of trapped lung (6.1%) is consistent with reports from other centers and typically resolves with appropriate post-operative management. The short hospital stay (75.4% discharged within one week) reflects both the effectiveness of the surgical approach and good postoperative management protocols. This compares favorably with other series and has important implications for healthcare resource utilization in resource-limited settings. Limitations Several limitations must be acknowledged when interpreting the results of this study. The retrospective design inherently carries the risk of information bias due to incomplete or inaccurate medical record data. As a single-center study from a tertiary referral hospital, our results may not be generalizable to all of Yemen, and there may be a selection bias toward more severe or complicated cases that require referral to specialized centers. The use of telephone follow-up for data collection could introduce recall bias, particularly for historical information on symptoms and exposure. The lack of complete serological data for all patients limited our ability to confirm the diagnosis, despite all cases being surgically confirmed to be the same. The descriptive nature of this study precludes the establishment of causal relationships, and the relatively short follow-up period does not provide information on long-term outcomes or recurrence rates. Additionally, the study period coincided with the ongoing conflict in Yemen, which may have affected healthcare access and patient presentation patterns, potentially influencing observed demographic and clinical characteristics. The correction of our initial data errors, while improving accuracy, highlights the importance of rigorous data verification in retrospective studies. Clinical Implications Our findings have several important clinical implications. The predominant involvement of young, economically productive individuals highlights the socioeconomic impact of this disease in Yemen. The high symptom burden at presentation underscores the need for increased awareness among healthcare providers, particularly in urban areas where most patients now reside, to facilitate the early diagnosis and treatment of this condition. The excellent surgical outcomes achieved at this specialized center support the centralization of care for complex cases and underscore the importance of surgical expertise in managing pulmonary hydatid cysts. The low complication rates and short hospital stays demonstrate that these procedures can be safely performed in appropriately equipped centers, even in resource-limited settings such as ours. Conclusions Pulmonary hydatid cysts in Yemen predominantly affect young males from urban areas and present with typical respiratory symptoms, including cough and dyspnea. Most cases involve solitary, intact cysts located in the right lung, although a significant proportion present with complications, such as cyst rupture. Surgical management with capitonnage is safe and effective when performed at specialized centers, with excellent outcomes and low morbidity rates. These findings emphasize the importance of hydatid disease as a public health concern in Yemen and support the effectiveness of conservative surgical approaches by experienced surgeons. Future efforts should focus on prevention strategies, early diagnosis programs, and ensuring access to specialized surgical care for affected populations. Abbreviations CI: Confidence Interval CT: Computed Tomography SPSS: Statistical Package for the Social Sciences TMGH: Al-Thawra Modern General Hospital SD: Standard Deviation Declarations Ethics Approval and Consent to Participate Ethical approval for this study was obtained from the Ethics Committee of the Faculty of Medicine and Health Sciences, Sana’a University. Administrative approval and permission to access patient medical records were granted by the administration of Al-Thawra Modern General Hospital (TMGH). All data were anonymized to ensure patient confidentiality. As this was a retrospective study of medical records, the requirement for informed consent was waived by the Ethics Committee. Trial registration Not applicable. Consent for Publication Not applicable. Availability of Data and Materials The datasets used and/or analyzed in this study are available from the corresponding author upon reasonable requests. Competing Interests The authors declare no conflict of interest. Funding This research did not receive any specific grants from any funding agency in the public, commercial, or not-for-profit sectors. Authors' Contributions MEN designed the study, collected data, and drafted the manuscript. MMA and YAO supervised the project and provided critical revisions of the manuscript. HMJ contributed to the statistical analysis and interpretation of data. All authors contributed to the data analysis and interpretation. All authors have read and approved the final manuscript. Acknowledgements The authors would like to thank the administrative staff and the Department of Thoracic Surgery at Al-Thawra Modern General Hospital for their support in accessing the medical records required for this study. References Nasr B, Al_junaeed A, Al Sady G, Al Shehari A, Amri A, Issa M, et al. Lung Hydatid Cysts in Children, Evaluation and Surgical Management. Journal of Cancer Science and Clinical Therapeutics. 2023;07. https://doi.org/10.26502/jcsct.5079189. Kocaman OH, Günendi T, Dere O, Dörterler ME, Boleken ME. Pulmonary Hydatid Cyst in Children: A Single-Institution Experience. Cureus. 2022. https://doi.org/10.7759/cureus.26670. Al-Shibani LAN, Al-Eryani SMA, Azazy AA, Al-Mekhlafi AM. Cases of hydatidosis in patients referred to Governmental hospitals for cyst removal in Sana’a City, Republic of Yemen. Tropical biomedicine. 2012;29:18–23. Alghoury A, El-Hamshary E, Azazy A, Hussein E, Rayan H. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9248949","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":622929585,"identity":"aaf7ee57-f4bc-4038-8490-3327a98da9eb","order_by":0,"name":"Mohammed M. Al-Shehari","email":"","orcid":"","institution":"Sana'a University","correspondingAuthor":false,"prefix":"","firstName":"Mohammed","middleName":"M.","lastName":"Al-Shehari","suffix":""},{"id":622929586,"identity":"eafc2faf-ed45-448b-a482-18d95c646e1e","order_by":1,"name":"Yasser Abdurabo Obadiel","email":"","orcid":"","institution":"Sana'a University","correspondingAuthor":false,"prefix":"","firstName":"Yasser","middleName":"Abdurabo","lastName":"Obadiel","suffix":""},{"id":622929587,"identity":"86a372fb-dd36-4b12-81f5-17f7f357e1c6","order_by":2,"name":"Mugahed Esmail Nahshal","email":"","orcid":"","institution":"Al-Thawra Modern General Hospital","correspondingAuthor":false,"prefix":"","firstName":"Mugahed","middleName":"Esmail","lastName":"Nahshal","suffix":""},{"id":622929588,"identity":"5fa0c7d2-8159-4f1d-a9af-5d02d12d90c5","order_by":3,"name":"Haitham Mohammed Jowah","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAzUlEQVRIiWNgGAWjYBACAwaGBCB1QA7M4yFFizFJWkDgQGID0VrMGRgePuapuZM+f0YC44O3bQyJ/YS0WDYwJBvzHHuWu+FGArPhXKCWmQ2EHHaAIU06h+1w7gaJBDZpXqCWDQeI0vLvcLr8jAT23yAt+4nSktt2OIHhRgIbM9gWQn4xOAz0y9++w4YbzjxslpxzTsJ4BkFbjvckPpzx7bC8fHvywQ9vymxk+xsIWcPMkwBlMYLUSjgS1MHAwI7qEHvCOkbBKBgFo2CkAQCEAUMIrb03fgAAAABJRU5ErkJggg==","orcid":"","institution":"Sana'a University","correspondingAuthor":true,"prefix":"","firstName":"Haitham","middleName":"Mohammed","lastName":"Jowah","suffix":""}],"badges":[],"createdAt":"2026-03-28 01:38:33","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9248949/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9248949/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":107255846,"identity":"665e06a1-f5ed-4e06-b10c-b61f3d571a19","added_by":"auto","created_at":"2026-04-19 12:12:26","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":86380,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eFlow diagram of patient selection for the study.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFlowchart illustrating the identification, screening, and inclusion processes. Of the 140 identified records, 26 were excluded due to recurrent disease (n=8), incomplete medical records (n=12), or refusal of surgical intervention (n=6), resulting in a final study sample of 114 patients.\u003c/p\u003e","description":"","filename":"Figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-9248949/v1/9c362cceb1c68f447d368d98.png"},{"id":107484599,"identity":"de105c05-fa45-4253-b839-ca9a331ff9a2","added_by":"auto","created_at":"2026-04-22 02:32:28","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":73206,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eDistribution of solitary and multiple pulmonary hydatid cysts.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eBar chart comparing the frequency of solitary and multiple cysts in the study population (N = 114). Solitary cysts were the most common finding, occurring in 85.1% of patients (95% CI: 77.4%–90.5%), whereas multiple cysts were observed in 14.9% (95% CI: 9.5%–22.6%).\u003c/p\u003e","description":"","filename":"Figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-9248949/v1/c211bbd9a28fa573bef2912b.png"},{"id":107255848,"identity":"4e55ffe4-a5e5-42e4-9378-8ecf684d3e5f","added_by":"auto","created_at":"2026-04-19 12:12:26","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":149423,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eAnatomical and size distribution of solitary pulmonary hydatid cysts.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMulti-panel figure detailing the characteristics of solitary cysts. (A) Distribution by lung side and lobe (n = 97), showing a predilection for the right lung (67.0%). (B) Distribution of maximum cyst diameter (n = 86), where 62.8% of cysts measured between 5.0 and 9.9 cm.\u003c/p\u003e","description":"","filename":"Figure3.png","url":"https://assets-eu.researchsquare.com/files/rs-9248949/v1/e6dfd3b28cc6f6522eb34693.png"},{"id":107255849,"identity":"56d47f2a-185f-4f89-bed6-272b61dc8591","added_by":"auto","created_at":"2026-04-19 12:12:27","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":59530,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eExtrapulmonary hydatid cyst involvement.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eHorizontal bar chart showing the proportion of patients with isolated pulmonary disease versus those with concurrent extrapulmonary involvement (N = 114). All 12 patients (10.5%; 95% CI: 6.0%–17.4%) with extrapulmonary disease had concurrent hydatid cysts in the liver.\u003c/p\u003e","description":"","filename":"Figure4.png","url":"https://assets-eu.researchsquare.com/files/rs-9248949/v1/8e735f44bcc10b6b7a04141b.png"},{"id":107487188,"identity":"4d32c3ce-43a2-4fca-a0da-e37b97b76341","added_by":"auto","created_at":"2026-04-22 02:39:58","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":894717,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9248949/v1/f0faa7ce-483b-4075-b95b-202560c5e4bb.pdf"},{"id":107255845,"identity":"b82019f6-6323-49d0-9169-e1b0ee27a0d6","added_by":"auto","created_at":"2026-04-19 12:12:26","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":212778,"visible":true,"origin":"","legend":"","description":"","filename":"STROBEChecklist.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9248949/v1/32dae3097c94875aa02c5b79.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Clinical and radiological presentations of pulmonary hydatid cysts in Yemen: a retrospective cross-sectional study at a tertiary center","fulltext":[{"header":"Background","content":"\u003cp\u003ePulmonary hydatid cysts, caused by the larval stage of \u003cem\u003eEchinococcus granulosus\u003c/em\u003e, are among the most geographically widespread zoonotic diseases affecting humans. This disease poses significant medical, social, and economic burdens, particularly in endemic regions, and affects over one million people worldwide [1]. The parasite has the highest prevalence in parts of North Africa, Asia, South America, and Australia, with an annual human incidence exceeding 50 per 100,000 in endemic areas [2].\u003c/p\u003e\n\u003cp\u003eYemen, located on the Arabian Peninsula, is a hyperendemic region for hydatid disease owing to its pastoral economy, close human-animal contact, and poor sanitation. The disease is particularly prevalent in rural areas, where livestock farming is the primary occupation\u0026nbsp;and traditional practices facilitate parasite transmission\u0026nbsp;[3]. Previous studies from Yemen have documented the widespread nature of this parasitic infection, with significant\u0026nbsp;case loads reported in major governmental hospitals in Sana\u0026apos;a [4].\u003c/p\u003e\n\u003cp\u003eThe clinical presentation of pulmonary hydatid cysts varies considerably depending on cyst size, location, and the presence of complications. While small, intact cysts may remain asymptomatic for years, larger cysts or those with complications can present with respiratory symptoms, including cough, dyspnea, chest pain, and hemoptysis\u0026nbsp;[5, 6]. Radiological diagnosis, primarily via computed tomography, remains the cornerstone, revealing characteristic features such as well-defined cystic lesions with varying internal architectures\u0026nbsp;[7].\u003c/p\u003e\n\u003cp\u003eDespite the recognized burden of hydatid disease in Yemen, there is a paucity of recent comprehensive data on the clinical and radiological presentation of pulmonary hydatid cysts in the Yemeni population. Most available studies are either outdated or focus on general hydatid disease rather than pulmonary manifestations. This knowledge gap hampers the development of evidence-based diagnostic and treatment guidelines tailored to the local disease context of the region.\u003c/p\u003e\n\u003cp\u003eTherefore, this study aimed to evaluate the clinical and radiological presentations of pulmonary hydatid cysts at a major tertiary center in Sana\u0026apos;a, Yemen, over 4 years. The specific objectives included determining the sociodemographic characteristics of affected patients, documenting clinical presentations, characterizing radiological findings (including cyst number, size, location, and complications), and evaluating surgical management outcomes and early postoperative complications.\u003c/p\u003e"},{"header":"Methods","content":"\u003ch2\u003eStudy Design and Setting\u003c/h2\u003e\n\u003cp\u003eThis retrospective descriptive cross-sectional study was conducted at the Al-Thawra Modern General Hospital (TMGH) in Sana\u0026apos;a, Yemen. TMGH is a tertiary referral center with a specialized thoracic surgery unit and serves as one of the primary hospitals for complex thoracic procedures in Yemen.\u003c/p\u003e\n\u003ch2\u003eStudy Period and Population\u003c/h2\u003e\n\u003cp\u003eThis study covered a four-year and three-month period from January 1, 2019, to March 31, 2023. The source population comprised all patients admitted to the thoracic surgery unit with a diagnosis of pulmonary hydatid cysts during the study period.\u003c/p\u003e\n\u003ch2\u003eParticipant Selection\u003c/h2\u003e\n\u003cp\u003eA total of 140 patient records were initially identified in hospital databases. The inclusion criteria were as follows: (1) male or female patients aged 3-60 years, (2) patients with a clinical history and radiological findings consistent with pulmonary hydatid cysts; and (3) patients who underwent surgical intervention for pulmonary hydatid cysts. The exclusion criteria were as follows: (1) patients with recurrent hydatid lung disease, (2) patients who did not undergo surgical treatment, (3) patients with incomplete medical records, (4) patients who were unreachable for follow-up or refused to participate, and (5) records with insufficient data for analysis.\u003c/p\u003e\n\u003cp\u003eAfter applying these criteria, 26 records were excluded: 8 for recurrent disease, 12 for incomplete data, and 6 for refusal to undergo a surgical intervention. The final study sample comprised 114 patients with complete data available for analysis (Figure 1).\u003c/p\u003e\n\u003ch2\u003eData Collection\u003c/h2\u003e\n\u003cp\u003eData were collected using a structured questionnaire developed based on previous studies. The questionnaire captured (1) sociodemographic characteristics (age, sex, residence, occupation, and social habits), (2) clinical presentation (symptoms and their duration), (3) radiological findings (number, size, location, and condition of cysts), (4) surgical procedures performed, and (5) early postoperative complications and duration of hospitalization.\u003c/p\u003e\n\u003cp\u003eData were extracted from hospital medical records archives. Additional information was obtained by telephone from patients using their recorded contact information, and verbal informed consent was obtained for participation.\u003c/p\u003e\n\u003cp\u003eTo minimize selection bias, consecutive patients who met the inclusion criteria were included during the study period. Information bias was mitigated through the use of a structured questionnaire and verification of medical records. Recall bias during telephone follow-up was minimized by using standardized questions. The retrospective design inherently carries the risk of missing data; however, only records with complete data were included to ensure analytical completeness.\u003c/p\u003e\n\u003ch2\u003eVariables\u003c/h2\u003e\n\u003cp\u003eThe primary variables included patient demographics, clinical symptoms at presentation, radiological characteristics of hydatid cysts, surgical interventions performed, and postoperative outcomes. Radiological findings were categorized based on cyst number (solitary vs. multiple), anatomical location (lung side and lobe), cyst condition (intact, ruptured, infected), size, and associated complications.\u003c/p\u003e\n\u003ch2\u003eStatistical Analysis\u003c/h2\u003e\n\u003cp\u003eData were analyzed using IBM SPSS Statistics version 28.0 (IBM Corp.. Armonk, NY, USA). Descriptive statistics are presented as frequencies and percentages for categorical variables. Ninety-five percent confidence intervals (95% CI) were calculated for all proportions using the Wilson score method with continuity correction. Multiple-response analysis was used for variables in which patients could provide multiple responses, such as clinical symptoms and radiological findings. Chi-square tests were used to examine the associations between categorical variables, with p \u0026lt; 0.05 considered statistically significant.\u003c/p\u003e\n\u003ch2\u003eEthical Considerations\u003c/h2\u003e\n\u003cp\u003eEthical approval for this study was obtained from the Ethics Committee of the Faculty of Medicine and Health Sciences, Sana\u0026rsquo;a University, Sana\u0026rsquo; a, Yemen. Administrative approval and permission to access patient medical records were granted by the administration of Al-Thawra Modern General Hospital (TMGH). All data were anonymized to ensure patient confidentiality. As this was a retrospective study of medical records, the requirement for informed consent was waived by the Ethics Committee.\u003c/p\u003e\n\u003ch2\u003eAI Disclosure Statement\u003c/h2\u003e\n\u003cp\u003eThis manuscript was prepared with the assistance of Kimi (Moonshot AI) for formatting compliance verification and Grammarly and Paperpal for language editing and grammar correction. All content was reviewed, verified, and approved by the authors, who took full responsibility for the accuracy and integrity of the work.\u003c/p\u003e"},{"header":"Results","content":"\u003ch2\u003eParticipant Characteristics\u003c/h2\u003e\n\u003cp\u003eThe final study sample comprised 114 patients with surgically confirmed pulmonary hydatid cysts. The sociodemographic characteristics of the participants are summarized in Table 1. A marked male predominance was observed, with 82 males (71.9%; 95% CI: 63.1%-79.4%) and 32 females (28.1%; 95% CI: 19.9%-36.9%). The largest age group was 19-30 years (n=49, 43.0%; 95% CI: 34.3%-52.2%). Contrary to initial assumptions, most patients resided in urban areas (n=86, 75.4%; 95% CI: 66.8%-82.4%) rather than rural areas (n=28, 24.6%; 95% CI: 17.6%-33.2%). Occupation analysis revealed that 35.1% (95% CI: 26.9%-44.2%) were workers or laborers, 33.3% (95% CI: 25.3%-42.4%) were students, and 21.9% (95% CI: 15.3%-30.4%) were housewives. A history of khat chewing was reported by 57 patients (50.0%; 95% CI: 41.0%-59.0%).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 1. Sociodemographic characteristics of 114 patients with pulmonary hydatid cysts\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"100%\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eCharacteristic\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eCategory\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u003cstrong\u003en\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e%\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e95% CI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003eGender\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003eMale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e82\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e71.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e63.1-79.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003eFemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e32\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e28.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e19.9-36.9\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003eAge Group (years)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u0026lt;3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e0.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e0.2-4.8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e3-18\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e27.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e19.9-36.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e19-30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e43.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e34.3-52.2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e31-45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e23\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e20.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e13.8-28.5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e46-60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e8.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e4.8-15.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003eResidence\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003eUrban\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e86\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e75.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e66.8-82.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003eRural\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e24.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e17.6-33.2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003eOccupation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003eWorkers\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e35.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e26.9-44.2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003eStudents\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e38\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e33.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e25.3-42.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003eHousewives\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e21.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e15.3-30.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003eOther/Unknown\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e9.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e5.5-16.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003eKhat Chewing\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e57\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e50.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e41.0-59.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003eNo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e57\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e50.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e41.0-59.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003ch2\u003e\u003cbr\u003e\u003c/h2\u003e\n\u003ch2\u003eClinical Presentation\u003c/h2\u003e\n\u003cp\u003eThe clinical findings at diagnosis are presented in Table 2. Respiratory symptoms were almost universal. The most common presenting symptom was cough, reported in 102 patients (89.5%; 95% CI: 82.5%-93.9%), followed by dyspnea (n=87, 76.3%; 95% CI: 67.7%-83.2%) and chest pain (n=74, 64.9%; 95% CI: 55.8%-73.1%). Constitutional symptoms, such as fever, were also frequent (n=62, 54.4%; 95% CI: 45.2%-63.2%). Hemoptysis was noted in 36 patients (31.6%; 95% CI: 23.8%-40.6%), and the pathognomonic sign of expectorating grape-like material was reported by 9 patients (7.9%; 95% CI: 4.2%-14.3%).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2. Clinical presentation of 114 patients with pulmonary hydatid cysts at diagnosis\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"100%\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eClinical Symptom\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e\u003cstrong\u003en\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e%\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e95% CI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eCough\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e102\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e89.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e82.5-93.9\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eDyspnea\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e87\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e76.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e67.7-83.2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eChest pain\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e74\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e64.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e55.8-73.1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eFever\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e62\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e54.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e45.2-63.2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eHemoptysis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e36\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e31.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e23.8-40.6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eLoss of appetite\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e13.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e8.1-20.6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eWeight loss\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e11.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e6.8-18.5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eGrape-like material\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e7.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e4.2-14.3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eNausea/vomiting\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e2.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e0.9-7.5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003ch2\u003eRadiological Findings\u003c/h2\u003e\n\u003cp\u003eRadiological analysis revealed that the vast majority of patients (n=97, 85.1%; 95% CI: 77.4%-90.5%) presented with a solitary cyst, whereas 17 patients (14.9%; 95% CI: 9.5%-22.6%) had multiple cysts (Figure 2).\u003c/p\u003e\n\u003cp\u003eThe characteristics of the solitary cysts are further detailed in Table 3. A clear predilection for the right lung was observed, which contained 67.0% (95% CI: 57.2%-75.6%) of all solitary cysts, compared to 33.0% (95% CI: 24.4%-42.8%) in the left lung. Most of these cysts were intact at the time of diagnosis (n=74, 76.3%; 95% CI: 66.9%-83.6%). Among the 21 complicated solitary cysts, 21.6% (95% CI: 14.6%-30.8%) were ruptured and 2.1% (95% CI: 0.6%-7.2%) were infected. Bronchial rupture was the most common pathway (57.1%; 95% CI: 36.5%-75.5% of ruptures), followed by pleural space rupture (38.1%; 95% CI: 20.8%-59.1%). In terms of size, most solitary cysts measured between 5 and 9.9 cm in diameter (62.8%; 95% CI: 52.2%-72.3%), with giant cysts (\u0026gt;15 cm) being less common (9.3%; 95% CI: 4.8%-17.3%) (Figure 3).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3. Radiological findings of solitary pulmonary hydatid cysts (n = 97)\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"100%\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eCharacteristic\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eCategory\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u003cstrong\u003en\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e%\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e95% CI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003eCyst Condition\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003eIntact\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e74\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e76.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e66.9-83.6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003eRuptured\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e21.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e14.6-30.8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003eInfected\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e2.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e0.6-7.2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003eSide\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003eRight\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e65\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e67.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e57.2-75.6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003eLeft\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e32\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e33.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e24.4-42.8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003eRupture Site (n=21)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003eBronchus\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e57.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e36.5-75.5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003ePleura\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e38.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e20.8-59.1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003ePericardium\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e4.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e0.8-22.7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003eSize (n=86)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u0026lt;5 cm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e8.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e4.0-15.9\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e5-9.9 cm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e54\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e62.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e52.2-72.3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e10-15 cm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e19.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e12.7-29.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u0026gt;15 cm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e9.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e4.8-17.3\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\u003eIn the 17 patients with multiple cysts, 36 individual cysts were identified. In contrast to solitary cases, these were predominantly located in the left lung (61.1% of\u0026nbsp;cysts). Similar to the solitary cohort, most of these multiple cysts were intact (75.0%) and typically measured less than 10 cm in diameter.\u003c/p\u003e\n\u003cp\u003eConcurrent extrapulmonary disease was documented in 12 patients (10.5%; 95% CI: 6.0%-17.4%), all of whom were found to have associated liver hydatid cysts in addition to their pulmonary disease (Figure 4).\u003c/p\u003e\n\u003ch2\u003eSurgical Management and Outcomes\u003c/h2\u003e\n\u003cp\u003eConservative, lung-sparing surgery was the primary treatment.\u0026nbsp;Capitonnage was performed in 104 patients (91.2%; 95% CI: 84.6%-95.2%). Simple endocystectomy with capitonnage only was performed in 39 patients (34.2%; 95% CI: 26.1%-43.3%), while 70 patients (61.4%; 95% CI: 52.2%-69.8%) required complex procedures, including additional decortication, drainage, fistula closure, or lobectomy (Table 4).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 4. Surgical procedures performed in 114 patients with pulmonary hydatid cysts\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"100%\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eSurgical Procedure\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e\u003cstrong\u003en\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e%\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e95% CI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eCapitonnage (any)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e104\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e91.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e84.6-95.2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eSimple (Endo+Cap only)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e39\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e34.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e26.1-43.3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eComplex (+deco/drain/lobe)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e61.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e52.2-69.8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eOther/Unknown\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e4.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e1.9-9.8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eThe postoperative outcomes are shown in Table 5. The overall postoperative complication rate was low at 7.9% (95% CI: 4.2%-14.3%). The most frequent complication was an unexpanded (trapped) lung, which occurred in seven patients (6.1%; 95% CI: 3.0%-12.1%), followed by pneumonia in two patients (1.8%; 95% CI: 0.5%-6.2%). No postoperative mortality was observed in this study. The majority of patients (n=86, 75.4%; 95% CI: 66.8%-82.4%) had a short hospital stay of less than one week. The mean hospital stay was 6.43 \u0026plusmn; 5.88 days (range: 3-45 days).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 5. Postoperative outcomes in 114 patients with pulmonary hydatid cysts\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"100%\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eOutcome\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e\u003cstrong\u003en\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e%\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e95% CI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eAny Complication\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e7.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e4.2-14.3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eNo Complication\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e105\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e92.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e85.7-95.8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eComplication Type:\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eTrapped lung\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e6.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e3.0-12.1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003ePneumonia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e1.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e0.5-6.2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eHospital Stay:\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e\u0026lt;7 days\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e86\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e75.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e66.8-82.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e7-14 days\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e18.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e12.4-26.5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e\u0026gt;14 days\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e6.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003e3.0-12.1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cem\u003eMean hospital stay: 6.43 \u0026plusmn; 5.88 days (Range: 3-45 days). No mortality was observed.\u003c/em\u003e\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study provides comprehensive data on pulmonary hydatid cysts from a major tertiary center in Yemen over the past four years. Our findings confirmed that the disease predominantly affects young males from urban areas and\u0026nbsp;is characterized by respiratory symptoms. The radiological pattern shows a predominance of solitary, intact cysts, and surgical management demonstrates excellent outcomes with low complication rates when performed in specialized centers.\u003c/p\u003e\n\u003cp\u003eThe marked male predominance (71.9%) observed in our study is consistent with several regional studies but exceeds the proportions reported in some international studies.\u0026nbsp;Sheikhy et al. [8] reported a 55% male predominance in Iran, whereas Abdennadher et al. [9] found a more balanced sex distribution (51.51% male) in Tunisia than in Iran. The higher male predominance in our study may reflect occupational and cultural factors specific to Yemen, where men are more likely to engage in livestock-related activities and have greater exposure to infected animals\u0026nbsp;than are women.\u003c/p\u003e\n\u003cp\u003eThe concentration of cases in the young adult age group (19-30 years, 43.0%) aligns with findings from similar regions with endemicity. Aldahmashi et al. [10] reported an average age of 27.75 years in a multicenter study conducted in Yemen, Egypt, and Saudi Arabia, whereas Thapaliya et al. [11] reported a mean age of 31.11 years in Pakistan. This age distribution likely reflects the long incubation period of the disease and peak exposure during childhood and adolescence in endemic areas.\u003c/p\u003e\n\u003cp\u003eAn important finding of our analysis is that the majority of patients (75.4%) resided in urban areas. This contrasts with our initial data and previous reports from the endemic regions. This urban predominance may reflect the referral patterns to our tertiary center, with urban patients having better access to specialized health care. The high prevalence of khat chewing (50.0%) represents a unique finding that may be related to rural lifestyle and socioeconomic factors rather than a direct causal relationship with H. cystic disease. Our analysis found no significant association between khat use and any clinical symptoms ( P \u0026gt; 0.05).\u003c/p\u003e\n\u003cp\u003eThe clinical presentation in our study, dominated by cough (89.5%) and dyspnea (76.3%), is consistent with that reported in the literature for endemic regions. Sheikhy et al. [8] reported cough in 59.8% and dyspnea in 31.1% of patients, whereas Mohammad et al. [12] found cough in 44.6% of Indian patients. The higher symptom rates in our study may indicate more advanced disease at presentation, possibly due to delayed medical consultation or limited access to healthcare facilities. In contrast to Kuzucu et al. [13], who reported chest pain as the most frequent symptom, our findings align with those of Sheikhy et al. [8], where cough was the predominant presenting complaint (89.5%).\u003c/p\u003e\n\u003cp\u003eThe presence of hemoptysis in 31.6% of our patients is notably higher than the 12-21% range reported in most studies [14]. This finding, along with the proportion of ruptured cysts (21.6%), suggests that many patients presented with complicated disease, emphasizing the need for early diagnosis and intervention in endemic areas.\u003c/p\u003e\n\u003cp\u003eThe predominance of solitary cysts (85.1%) in our study is consistent with that of previous studies. Kocaman et al.\u0026nbsp;[2]\u0026nbsp;reported solitary cysts in the majority of their Turkish pediatric population.\u0026nbsp;Simultaneously, right lung predominance (67.0%) aligns with anatomical factors related to bronchial anatomy and blood flow distribution.\u003c/p\u003e\n\u003cp\u003eThe size distribution, with most cysts measuring 5-9.9 cm (62.8%), suggests that patients presented with moderately sized cysts that were symptomatic but not yet at the giant cyst stage. This pattern differs from that reported in some studies, which reported higher proportions of giant cysts (\u0026gt;10 cm), possibly reflecting differences in healthcare access and timing of presentation [9].\u003c/p\u003e\n\u003cp\u003eThe rupture rate of 21.6% for solitary cysts falls within the range of 24.7%\u0026ndash;61% reported in the literature [15]. The predominant rupture into the bronchi (57.1%) versus the pleura (38.1%) has important clinical implications, as bronchial rupture typically presents with pathognomonic symptoms\u0026nbsp;such as\u0026nbsp;hydatoptysis. In contrast, pleural rupture can lead to serious complications, including empyema and pneumothorax.\u003c/p\u003e\n\u003cp\u003eThe high success rate of conservative surgical procedures (capitonnage in 91.2% of cases) demonstrates the effectiveness of lung-sparing techniques by experienced surgeon. This approach aligns with the current surgical philosophy, which favors parenchymal preservation\u0026nbsp;whenever possible\u0026nbsp;[16]. The low rate of lung resection (4.4%, including lobectomy and wedge resection) compares favorably with other series and reflects both appropriate patient selection and surgical expertise. Notably, while Abdennadher et al. [9] required anatomical resection in 45.46% of giant cyst cases, our series achieved high success with parenchyma-preserving capitonnage (91.2%), even in a cohort with significant cyst diameters.\u003c/p\u003e\n\u003cp\u003eThe overall complication rate of 7.9% and the absence of mortality in our series are excellent and compare favorably with the published literature reporting complication rates of up to 20% and mortality rates of 0-2%\u0026nbsp;[17]. The most common complication of trapped\u0026nbsp;lung (6.1%) is consistent with reports from other centers and typically resolves with appropriate post-operative management.\u003c/p\u003e\n\u003cp\u003eThe short hospital stay (75.4% discharged within one week) reflects both the effectiveness of the surgical approach and good postoperative management protocols. This compares favorably with other series and has important implications for healthcare resource utilization in resource-limited settings.\u003c/p\u003e\n\u003ch2\u003eLimitations\u003c/h2\u003e\n\u003cp\u003eSeveral limitations must be acknowledged when interpreting the results\u0026nbsp;of this study. The retrospective design inherently carries the risk of information bias due to incomplete or inaccurate medical record data. As a single-center study from a tertiary referral hospital, our results may not be generalizable to all of Yemen, and there may be a selection bias toward more severe or complicated cases that require referral to\u0026nbsp;specialized centers.\u003c/p\u003e\n\u003cp\u003eThe use of telephone follow-up for data collection could introduce recall bias, particularly for historical information on symptoms and exposure. The lack of complete serological data for all patients limited our ability to confirm the diagnosis, despite all cases being surgically confirmed to be the same. The descriptive nature of this study precludes the\u0026nbsp;establishment of causal relationships, and the relatively short follow-up period does not provide information on long-term outcomes or recurrence rates.\u003c/p\u003e\n\u003cp\u003eAdditionally, the study period coincided with the ongoing conflict in Yemen, which may have affected healthcare access and patient presentation patterns, potentially influencing observed demographic and clinical characteristics. The correction of our initial data errors, while improving accuracy, highlights the importance of rigorous data verification in retrospective studies.\u003c/p\u003e\n\u003ch2\u003eClinical Implications\u003c/h2\u003e\n\u003cp\u003eOur findings have several important clinical implications. The predominant involvement of young, economically productive individuals highlights the socioeconomic impact of this disease in Yemen. The high symptom burden at presentation underscores the need for increased awareness among healthcare providers, particularly in urban areas where most patients now reside, to facilitate the early diagnosis and treatment\u0026nbsp;of this condition.\u003c/p\u003e\n\u003cp\u003eThe excellent surgical outcomes achieved at this specialized center support the centralization of care for complex cases and underscore the importance of surgical expertise in managing pulmonary hydatid cysts. The low complication rates and short hospital stays demonstrate that these procedures can be safely performed in appropriately equipped centers, even in resource-limited settings such as ours.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003ePulmonary hydatid cysts in Yemen predominantly affect young males from urban areas and present with typical respiratory symptoms, including cough and dyspnea. Most cases involve solitary, intact cysts located in the right lung, although a significant proportion present with complications, such as cyst rupture. Surgical management with capitonnage is safe and effective when performed at specialized centers, with excellent outcomes and low morbidity rates. These findings emphasize the importance of hydatid disease as a public health concern in Yemen and support the effectiveness of conservative surgical approaches by experienced surgeons. Future efforts should focus on prevention strategies, early diagnosis programs, and ensuring access to specialized surgical care for affected populations.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003e\u003cstrong\u003eCI:\u003c/strong\u003e Confidence Interval\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCT:\u003c/strong\u003e Computed Tomography\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSPSS:\u003c/strong\u003e Statistical Package for the Social Sciences\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTMGH:\u003c/strong\u003e Al-Thawra Modern General Hospital\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSD:\u003c/strong\u003e Standard Deviation\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eEthics Approval and Consent to Participate\u003c/h2\u003e\n\u003cp\u003eEthical approval for this study was obtained from the Ethics Committee of the Faculty of Medicine and Health Sciences, Sana\u0026rsquo;a University. Administrative approval and permission to access patient medical records were granted by the administration of Al-Thawra Modern General Hospital (TMGH). All data were anonymized to ensure patient confidentiality. As this was a retrospective study of medical records, the requirement for informed consent was waived by the Ethics Committee.\u003c/p\u003e\n\u003ch2\u003eTrial registration\u003c/h2\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003ch2\u003eConsent for Publication\u003c/h2\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003ch2\u003eAvailability of Data and Materials\u003c/h2\u003e\n\u003cp\u003eThe datasets used and/or analyzed in this study are available from the corresponding author upon reasonable requests.\u003c/p\u003e\n\u003ch2\u003eCompeting Interests\u003c/h2\u003e\n\u003cp\u003eThe authors declare no conflict of interest.\u003c/p\u003e\n\u003ch2\u003eFunding\u003c/h2\u003e\n\u003cp\u003eThis research did not receive any specific grants from any funding agency in the public, commercial, or not-for-profit sectors.\u003c/p\u003e\n\u003ch2\u003eAuthors\u0026apos; Contributions\u003c/h2\u003e\n\u003cp\u003eMEN designed the study, collected data, and drafted the manuscript. MMA and YAO supervised the project and provided critical revisions of the manuscript. HMJ contributed to the statistical analysis and interpretation\u0026nbsp;of data. All authors contributed to\u0026nbsp;the data analysis and interpretation. All authors have read and approved the final manuscript.\u003c/p\u003e\n\u003ch2\u003eAcknowledgements\u003c/h2\u003e\n\u003cp\u003eThe authors would like to thank the administrative staff and the Department of Thoracic Surgery at Al-Thawra Modern General Hospital for their support in accessing the medical records required for this study.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eNasr B, Al_junaeed A, Al Sady G, Al Shehari A, Amri A, Issa M, et al. Lung Hydatid Cysts in Children, Evaluation and Surgical Management. Journal of Cancer Science and Clinical Therapeutics. 2023;07. https://doi.org/10.26502/jcsct.5079189.\u003c/li\u003e\n\u003cli\u003eKocaman OH, G\u0026uuml;nendi T, Dere O, D\u0026ouml;rterler ME, Boleken ME. Pulmonary Hydatid Cyst in Children: A Single-Institution Experience. Cureus. 2022. https://doi.org/10.7759/cureus.26670.\u003c/li\u003e\n\u003cli\u003eAl-Shibani LAN, Al-Eryani SMA, Azazy AA, Al-Mekhlafi AM. Cases of hydatidosis in patients referred to Governmental hospitals for cyst removal in Sana\u0026rsquo;a City, Republic of Yemen. Tropical biomedicine. 2012;29:18\u0026ndash;23.\u003c/li\u003e\n\u003cli\u003eAlghoury A, El-Hamshary E, Azazy A, Hussein E, Rayan H. Hydatid Disease in Yemeni Patients attending Public and Private Hospitals in Sana\u0026rsquo;a City, Yemen. Oman Medical Journal. 2010;25:88\u0026ndash;90. https://doi.org/10.5001/omj.2010.26.\u003c/li\u003e\n\u003cli\u003eDarwish B. Clinical and radiological manifestations of 206 patients with pulmonary hydatidosis over a ten-year period. Primary Care Respiratory Journal. 2006;15. https://doi.org/10.1016/j.pcrj.2006.05.006.\u003c/li\u003e\n\u003cli\u003eKanat F, Turk E, Aribas OK. Comparison of pulmonary hydatid cysts in children and adults. ANZ Journal of Surgery. 2004;74. https://doi.org/10.1111/j.1445-1433.2004.03022.x.\u003c/li\u003e\n\u003cli\u003eAydin Y, Ulas AB, Ince I, Kalin A, Can FK, Gundogdu B, et al. Evaluation of albendazole efficiency and complications in patients with pulmonary hydatid cyst. Interactive Cardiovascular and Thoracic Surgery. 2022;34. https://doi.org/10.1093/icvts/ivab259.\u003c/li\u003e\n\u003cli\u003eSheikhy K, Rouhani R, Pejhan S, Motlagh AS, Sheikhy A. Evaluation of clinical status, diagnosis, treatment and radiological findings of pulmonary hydatid cyst: 5-years\u0026rsquo; experience at tertiary lung center. Caspian Journal of Internal Medicine. 2022;13. https://doi.org/10.22088/cjim.13.1.44.\u003c/li\u003e\n\u003cli\u003eAbdennadher M, Hadj Dahmane M, Zribi H, Zairi S, Bouassida I, Sahnoun I, et al. Management of giant hydatid cysts: a tertiary centre experience. The Cardiothoracic Surgeon. 2021;29:11. https://doi.org/10.1186/s43057-021-00048-1.\u003c/li\u003e\n\u003cli\u003eAldahmashi M, Alassal M, Kasb I, Elrakhawy H. Conservative Surgical Management for Pulmonary Hydatid Cyst: Analysis and Outcome of 148 Cases. Canadian Respiratory Journal. 2016;2016:1\u0026ndash;6. https://doi.org/10.1155/2016/8473070.\u003c/li\u003e\n\u003cli\u003eThapaliya P, Ahmad T, Abid A, Sikander N, Mazcuri M, Ali N. Management Outcome in Simple and Complex Hydatid Cysts of Lung. Cureus. 2020. https://doi.org/10.7759/cureus.12212.\u003c/li\u003e\n\u003cli\u003eMohammad A, Benjamin SR, Narayanan D, Rao VM, Malampati S, Andugala SS, et al. Thoracic hydatid cysts: an analysis of surgical management in a tertiary care centre in India. Indian journal of thoracic and cardiovascular surgery. 2022;38:17\u0026ndash;27. https://doi.org/10.1007/s12055-021-01294-y.\u003c/li\u003e\n\u003cli\u003eKuzucu A, Ulutas H, Reha Celik M, Yekeler E. Hydatid cysts of the lung: Lesion size in relation to clinical presentation and therapeutic approach. Surgery Today. 2014;44. https://doi.org/10.1007/s00595-012-0484-2.\u003c/li\u003e\n\u003cli\u003eAhmadinejad M, Hashemi M, Azizallahi N. Evaluation of Prognostic Factors Associated with Postoperative Complications Following Pulmonary Hydatid Cyst Surgery. TORMJ. 2020;14:16\u0026ndash;21. https://doi.org/10.2174/1874306402014010016.\u003c/li\u003e\n\u003cli\u003eOnal O, Demir OF. The relation between the location and the perforation rate of lung hydatid cysts in children. Asian Journal of Surgery. 2018;41:422\u0026ndash;6. https://doi.org/10.1016/j.asjsur.2017.04.001.\u003c/li\u003e\n\u003cli\u003eHussen WM, Kadhim MA. Resection in pulmonary hydatid cyst (parasitic disease). Annals of Tropical Medicine \u0026amp; Public Health. 2021;24. https://doi.org/10.36295/ASRO.2021.24560.\u003c/li\u003e\n\u003cli\u003eMoradi M, Rampisheh Z, Roozbehani M, Razmjou E. A retrospective study of hydatid cysts in patients undergoing liver and lung surgery in Tehran, Iran. Heliyon. 2019;5. https://doi.org/10.1016/j.heliyon.2019.e01897.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"journal-of-cardiothoracic-surgery","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jcts","sideBox":"Learn more about [Journal of Cardiothoracic Surgery](http://cardiothoracicsurgery.biomedcentral.com)","snPcode":"13019","submissionUrl":"https://submission.nature.com/new-submission/13019/3","title":"Journal of Cardiothoracic Surgery","twitterHandle":"@BioMedCentral","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"hydatid cyst, echinococcosis, pulmonary, Yemen, cross-sectional study, surgical management.","lastPublishedDoi":"10.21203/rs.3.rs-9248949/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9248949/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground: \u003c/strong\u003ePulmonary hydatid cysts caused by \u003cem\u003eEchinococcus granulosus\u003c/em\u003e represent a significant health burden in endemic regions such as Yemen. Limited contemporary data are available on the clinical and radiological characteristics of this disease in the Yemeni population. This study aimed to evaluate the clinical presentation, radiological features, surgical management, and early outcomes of pulmonary hydatid cysts at a tertiary center in Sana'a, Yemen.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods:\u003c/strong\u003e This retrospective cross-sectional study was conducted at Al-Thawra Modern General Hospital between January 2019 and March 2023. The medical records of 114 patients with surgically confirmed pulmonary hydatid cysts were analyzed. Demographic data, clinical presentations, radiological findings, surgical procedures, and early postoperative complications were collected using a structured questionnaire. Statistical analyses were performed using SPSS v. 28.0, and 95% confidence intervals were calculated for all proportions.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e Of 114 patients, 82 (71.9%; 95% CI: 63.1%-79.4%) were male, with a predominant age group of 19-30 years (43.0%; 95% CI: 34.3%-52.2%). Most patients were from urban areas (75.4%; 95% CI: 66.8%-82.4%) and worked as laborers (35.1%) or students (33.3%). Khat chewing was reported by 50.0% (95% CI: 41.0%-59.0%) of the patients. The most common symptoms were cough (89.5%; 95% CI: 82.5%-93.9%), dyspnea (76.3%; 95% CI: 67.7%-83.2%), and chest pain (64.9%; 95% CI: 55.8%-73.1%). Radiologically, 97 patients (85.1%; 95% CI: 77.4%-90.5%) had solitary cysts, predominantly in the right lung (67.0%). Most cysts were intact (76.3%; 95% CI: 66.9%-83.6%) and ranged in size from 5 to 9.9 cm (62.8%). Capitonnage was performed in 91.2% (95% CI: 84.6%-95.2%) of the cases. Postoperative complications occurred in 7.9% (95% CI: 4.2%-14.3%) of patients, with no mortality reported. Hospital stay was less than 1 week for 75.4% (95% CI: 66.8%-82.4%) of patients.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions:\u003c/strong\u003e Pulmonary hydatid cysts in Yemen predominantly affect young urban males and present with respiratory symptoms. Solitary, intact cysts are the most common, and surgical management with capitonnage is safe and effective, with low morbidity rates when performed in specialized centers.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTrial registration:\u003c/strong\u003e Not applicable.\u003c/p\u003e","manuscriptTitle":"Clinical and radiological presentations of pulmonary hydatid cysts in Yemen: a retrospective cross-sectional study at a tertiary center","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-19 12:12:22","doi":"10.21203/rs.3.rs-9248949/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorInvitedReview","content":"","date":"2026-05-01T18:58:43+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-28T20:03:55+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-27T13:15:12+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"223487246821354313874420821272014078157","date":"2026-04-23T07:51:39+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"137176108458083446994099874704311801732","date":"2026-04-22T17:56:30+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"81088315772701655262560257560140571589","date":"2026-04-22T13:35:27+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"243920220156123216522392988941314101641","date":"2026-04-22T11:00:24+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"194413705602740949457864546250830410378","date":"2026-04-18T21:13:38+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-17T20:49:51+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"182817732916232460099035109717102591941","date":"2026-04-14T11:13:43+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"229465952090885563355312450338230503637","date":"2026-04-11T17:20:56+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"243579500345987408488612456237979446942","date":"2026-04-10T08:34:47+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"114851057370369496348459916532087718225","date":"2026-04-09T14:31:47+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-04-09T14:04:52+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-03-30T03:25:47+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-03-30T03:24:57+00:00","index":"","fulltext":""},{"type":"submitted","content":"Journal of Cardiothoracic Surgery","date":"2026-03-28T01:24:46+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"journal-of-cardiothoracic-surgery","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jcts","sideBox":"Learn more about [Journal of Cardiothoracic Surgery](http://cardiothoracicsurgery.biomedcentral.com)","snPcode":"13019","submissionUrl":"https://submission.nature.com/new-submission/13019/3","title":"Journal of Cardiothoracic Surgery","twitterHandle":"@BioMedCentral","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"05b1dc45-21cd-4e82-9c5d-7a0ba1efc3b1","owner":[],"postedDate":"April 19th, 2026","published":true,"recentEditorialEvents":[{"type":"editorInvitedReview","content":"","date":"2026-05-01T18:58:43+00:00","index":106,"fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-04-19T12:12:22+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-19 12:12:22","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9248949","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9248949","identity":"rs-9248949","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}