Intravascular EBUS-TBNA for Diagnosis of Primary Mediastinal Seminoma Invading the Superior Vena Cava: A Case Report

Intravascular EBUS-TBNA for Diagnosis of Primary Mediastinal Seminoma Invading the Superior Vena Cava: A Case Report | 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 Case Report Intravascular EBUS-TBNA for Diagnosis of Primary Mediastinal Seminoma Invading the Superior Vena Cava: A Case Report Esraa Mohammed Mohammed Hamza, Wael Mohamed Mostafa Emam, Fatma Samy Sayed Hafez, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8610442/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 32 You are reading this latest preprint version Abstract Background Mediastinal seminoma is a very rare extragonadal malignant germ cell tumor often misdiagnosed. Case presentation: A 27-year-old male presented with dyspnea. Imaging exhibited a mass invading the right upper lobe and extending to the anterior mediastinum and invading the superior vena cava (SVC). CT-guided biopsy showed necrotizing granulomas, and empiric antituberculosis therapy was initiated. The absence of clinical and radiological improvement after four months necessitated re-evaluation via EBUS-TBNA to reassess the diagnosis. EBUS-TBNA from the mass invading SVC through intravascular approach was performed without significant adverse events and yielded adequate tissue, with rapid on-site assessment and histopathology confirmed seminoma. Conclusions Intravascular EBUS-TBNA is a safe, minimally invasive technique for diagnosing primary mediastinal Seminoma invading the SVC. Endobronchial ultrasound Biopsy Fine-Needle Mediastinal Neoplasms Seminoma Vascular Neoplasms Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Primary mediastinal seminomas are exceedingly uncommon and were initially identified by Woolner and colleagues in 1955 ( 1 , 2 ). Germ cell tumors comprise only 1–4% of mediastinal tumors, with seminomas being the second most prevalent type after teratomas. Seminomas are slow-growing and frequently infiltrate local structures, often being substantial at the time of diagnosis ( 2 , 3 ). Primary mediastinal seminoma's pathogenesis remains incomplete; however, it may be associated with the retention and displacement of germ cells or pluripotent stem cells to the mediastinum, induction by carcinogenic factors, or ectopic gonadal tissue through embryonic development ( 4 , 5 ). Misdiagnosis and improper therapy are probable in the diagnosis and management of primary mediastinal seminoma. A complete diagnostic strategy is necessary, including clinical complaints, imaging studies, serum tumor markers, and validated by histology for a definitive diagnosis. ( 6 ). Case Presentation A 27-year-old male presented with no prior comorbid conditions and no history of smoking or any addiction. He reported a dry cough and progressive dyspnea (grade 3, Modified Medical Research Council [mMRC]) for the past 7 months. Computed tomography (CT) imaging and whole-body positron emission tomography-computed tomography (PET-CT) were performed. The results demonstrated a heterogeneously enhancing mass with areas of breakdown, infiltrating the right upper lobe and extending to the anterior mediastinum, abutting the right atrium as well as the superior vena cava (SVC) (Fig. 1 A, B). The greatest dimensions were 6.5 × 6.8 × 7.7 cm, with a maximum standardized uptake value (SUVmax) of 14.5 (Fig. 1 C, D). No other mediastinal lymph nodes were enlarged. The initial CT-guided biopsy showed necrotizing granulomas, which, in our TB-endemic setting, raised a strong clinical suspicion of tuberculosis. Empiric antituberculosis therapy was initiated. A repeated CT scan conducted four months later revealed an enlargement of the mass to 7.4 × 7.7 × 10.5 cm, accompanied by contralateral pleural effusion (Fig. 2 ) despite continuous antituberculosis medication. The absence of clinical and radiological improvement after four months necessitated re-evaluation to reassess the diagnosis. For additional evaluation and diagnosis, he was referred to our bronchoscopy unit. Presumably, the mass was classified as a mediastinal tumor due to its invasion of the SVC and its location. To obtain tissue samples for pathological diagnosis, we elected to conduct endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). EBUS-TBNA was conducted under general anesthesia. Conventional bronchoscopy (Pentax, EB1570K) was within the normal range, apart from a submucosal protrusion at the second and third intercartilaginous spaces above the carina between 12 and 2 o'clock. The EBUS bronchoscope (Pentax, EB-19-J10U; ARIETTA V60, ALOKA, HITACHI Ltd., Tokyo, Japan) at the level of the submucosal bulge at the site of right lower paratracheal lymph node (4R LN) showed multiple oval homogeneous appearing nodal structures with well-defined distinct borders, each measuring 0.8 cm, with no intranodal vessels, or calcification. The SVC was densely encased by the intravascular homogenous tumor mass, characterized by indistinct margins and the absence of necrosis, measuring 2.1 cm (Fig. 3 A). Blood flow was detected around the tumor on color Doppler imaging (Fig. 3 B). The tumor was punctured through a 22-gauge needle under real-time EBUS visualization, and three passes of EBUS-TBNA biopsies were successfully obtained from the intravascular mass inside the SVC (Fig. 4 ). Throughout the procedure, careful Doppler assessment was used to confirm the vascular nature of the mass and to select a relatively avascular puncture site within the SVC, ensuring optimal safety. Real-time EBUS guidance allowed precise needle placement into the intravascular tumor while avoiding injury to the vascular wall. To further enhance safety, the EBUS scope was firmly compressed against the vessel wall immediately after each needle pass to promote hemostasis. Rapid on-site evaluation (ROSE) confirmed sample adequacy after 3 needle passes, reducing the need for additional sampling and limiting procedural trauma. The procedure was completed without significant bleeding or other complications, and the patient was closely monitored post-procedure with no adverse events observed. Preliminary ROSE was done and revealed sheets of discohesive large neoplastic cells with scattered small lymphocytes in a bloody background (Fig. 5 A). Tissue biopsies and slides were sent for histopathological examination. Examination of the tissue block demonstrated dispersed large atypical epithelioid/ round cells having hyperchromatic pleomorphic nuclei, coarse chromatin, and prominent nucleoli, surrounded by scattered mature reactive lymphocytes in a bloody background (Fig. 5 B, C). Immunohistochemistry was performed using pan CK, SALL4, c-Kit, LCA, CD30, and glypican-3. The results revealed Positive staining of neoplastic cells to SALL4 and c-Kit. LCA showed negative staining of neoplastic cells with positivity of the reactive lymphocytes (Fig. 5 D, E, F). Pan CK, CD30, and glypican-3 were negative. These results led to a definitive diagnosis of mediastinal seminoma. Discussion EBUS-TBNA is a minimally invasive method used to examine lymph nodes in the mediastinum while providing real-time imaging of thoracic structures (7). EBUS-TBNA capability to detect abnormalities within mediastinal blood vessels, such as tumors or clots, has raised questions about whether these lesions can be safely sampled, particularly in patients for whom conventional surgical approaches are risky or unsuitable ( 8 ). In our case, EBUS-TBNA enabled us to obtain tissue from the intravascular mass inside the SVC without significant adverse events, avoiding the need for an undesirable thoracotomy under general anesthesia. The final histopathological diagnosis revealed mediastinal seminoma. A review of the literature highlights the rarity of primary mediastinal seminomas, with most diagnoses historically achieved via surgical or percutaneous biopsy [Table 1 ]. Li et al. and Petrova et al. reported individual cases diagnosed through needle and CT-guided approaches, while Napieralska et al. described a broader series spanning three decades ( 2 , 3 , 9 ). Notably, Zhang et al. reported successful diagnosis of a primary mediastinal seminoma through transbronchial mediastinal cryobiopsy, highlighting the ability of an EBUS-guided approach for the cryobiopsy to yield adequate tissue without surgical intervention( 10 ). Meanwhile, the application of EBUS-TBNA for transvascular and intravascular sampling has been increasingly recognized as a safe and effective diagnostic approach [Table 1 ]. Notably, Lee et al. successfully performed intravascular EBUS-TBNA on a tumor within the SVC, closely mirroring our case ( 7 ). Further evidence is provided by Harris et al. and Panchabhai et al., who collectively reported multiple transvascular and intravascular EBUS-TBNA cases with excellent safety profiles ( 8 , 11 ). Together, these reports emphasize the expanding role of EBUS-TBNA in the diagnosis of complex vascular tumors. Table 1 ( Expanded Literature Review) Author (Year) Condition/Diagnosis Biopsy Method Vascular Involvement Adverse events Key Findings Li and co-authors (2024) ( 9 ) Primary Mediastinal Seminoma with Azoospermia Needle Biopsy Not specified None Single case diagnosed via needle biopsy; highlighted azoospermia association. Napieralska and co-authors (2018) ( 2 ) Primary Mediastinal Seminoma (16 cases) 16 cases over 31 years; 6 diagnosed incidentally post-surgery Superior vena cava syndrome occurred in 19% of patients Not specified Focused primarily on treatment and clinical outcomes Petrova and co-authors (2019) ( 3 ) Primary Mediastinal Seminoma CT-Guided Biopsy Not specified None Single case; diagnosed with the presence of bilateral effusions Zhang and co-authors (2020) ( 10 ) Primary Mediastinal Seminoma EBUS guided Transbronchial mediastinal cryobiopsy Not specified slight bleeding EBUS–guided transbronchial mediastinal cryobiopsy is an effective approach for obtaining sufficient tissue biopsies Lee and co-authors (2016) ( 7 ) Lung Cancer with SVC Syndrome Intravascular EBUS-TBNA Superior Vena Cava None Demonstrated safety and efficacy of intravascular EBUS-TBNA for diagnosis. Harris and co-authors (2015) ( 8 ) Intravascular and transvascular lesions Intravascular and transvascular EBUS-TBNA Pulmonary Artery, descending aorta None Systematic review of multiple cases; safe and successful tissue acquisition. Panchabhai and co-authors (2015) ( 11 ) Transvascular Lesions Transvascular EBUS-TBNA Pulmonary artery and its branches. None Single-center experience of 10 cases; No adverse events reported. Similarly, in our case, EBUS-TBNA was successfully utilized to puncture the SVC without any adverse events. Building on previous reports and our experience, this case highlights that, when performed by skilled operators, intravascular and transvascular sampling through EBUS-TBNA can be considered a safe and effective approach. Limitations This case report is limited by its single-patient design, which restricts the ability to generalize the findings to broader patient populations. Additionally, while EBUS-TBNA was performed safely in this instance, further cases are needed to validate its safety and diagnostic reliability for intravascular tumors. Conclusion This case reinforces the expanding role of EBUS-TBNA as a safe, effective, and minimally invasive technique for diagnosing challenging intravascular mediastinal tumors. Our successful diagnosis of a rare mediastinal seminoma through intravascular biopsy highlights the procedure’s potential to access complex lesions previously considered difficult to sample without resorting to high-risk surgical approaches. Abbreviations EBUS-TBNA Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration SVC Superior Vena Cava CT Computed Tomography PET-CT Positron Emission Tomography - Computed Tomography SUVmax Maximum Standardized Uptake Value ROSE Rapid On-Site Evaluation mMRC Modified Medical Research Council (Dyspnea Scale). Declarations Ethical Approval and Informed Consent : Ethical approval for this case report was granted by the Ethical Committee of Ain Shams University. In addition, written informed consent was obtained from the patient for the publication of this report. Avaliability of data No data was produced or assessed in the course of this case report. Competing interests: The authors have no competing interests to disclose. Funding: This work was completed without any financial funding related to research, authorship, or publication. Author Contribution Ashraf Madkour: Conceptualization, supervision, critical revision of the manuscript, and final approval of the version to be published, Nehad Osman: Supervision, substantial contributions to clinical management, critical review of the manuscript, and final approval, Wael Emam: Case data collection, detailed literature review, clinical data analysis and editing, Esraa Hamza: Major contribution to manuscript writing, literature analysis, preparation of clinical figures, and substantial input in case discussion, Fatma Hafez: Histopathological examination, preparation and interpretation of pathology slides and images, contribution to the pathology discussion, and critical revision of pathology content. References Woolner LB, Jamplis RW, Kirklin JW (1955) Seminoma (germinoma) apparently primary in the anterior mediastinum. N Engl J Med 252(16):653–657 Napieralska A, Majewski W, Osewski W, Miszczyk L (2018) Primary mediastinal seminoma. J Thorac Dis 10(7):4335 Petrova D, Kraleva S, Muratovska L, Crcareva B (2019) Primary seminoma localized in mediastinum: case report. Open Access Maced J Med Sci 7(3):384 Xiu W, Pang J, Hu Y, Shi H (2023) Immune-related mechanisms and immunotherapy in extragonadal germ cell tumors. Front Immunol 14:1145788 Guida E, Tassinari V, Colopi A, Todaro F, Cesarini V, Jannini B et al (2022) MAPK activation drives male and female mouse teratocarcinomas from late primordial germ cells. J Cell Sci 135(8):jcs259375 Committee ACPR (2022) S Cancer in 2022. Cancer Discov. 2022;12(12):2733–8 Lee D, Moon SM, Kim D, Kim J, Chang H, Yang B et al (2016) Lung cancer with superior vena cava syndrome diagnosed by intravascular biopsy through EBUS-TBNA. Respir Med Case Rep 19:177–180 Harris K, Modi K, Kumar A, Dhillon SS (2015) Endobronchial ultrasound-guided transbronchial needle aspiration of pulmonary artery tumors: A systematic review (with video). Endosc Ultrasound 4(3):191–197 Li Z, Zhu Q, Niu S, Xiao K, Xiao Z, Yang P (2024) Primary mediastinal seminoma with azoospermia: case report and review of the literature. Front Oncol 14:1309803 Zhang J, Fu WL, Huang ZS, Guo JR, Li Q, Herth FJF et al (2020) Primary mediastinal seminoma achieved by transbronchial mediastinal cryobiopsy. Respiration 99(5):426–430 Panchabhai TS, Machuzak MS, Sethi S, Vijhani P, Gildea TR, Mehta AC et al (2015) Endobronchial Ultrasound–guided Transvascular Needle Aspiration: A Single-Center Experience. J Bronchol Interv Pulmonol 22(4):306–311 Additional Declarations No competing interests reported. Supplementary Files Needlebiopsy.mp4 Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 12 Mar, 2026 Reviews received at journal 08 Mar, 2026 Reviews received at journal 07 Mar, 2026 Reviews received at journal 07 Mar, 2026 Reviewers agreed at journal 04 Mar, 2026 Reviews received at journal 04 Mar, 2026 Reviewers agreed at journal 04 Mar, 2026 Reviews received at journal 03 Mar, 2026 Reviews received at journal 02 Mar, 2026 Reviewers agreed at journal 02 Mar, 2026 Reviews received at journal 02 Mar, 2026 Reviews received at journal 02 Mar, 2026 Reviews received at journal 01 Mar, 2026 Reviewers agreed at journal 01 Mar, 2026 Reviewers agreed at journal 01 Mar, 2026 Reviewers agreed at journal 01 Mar, 2026 Reviews received at journal 28 Feb, 2026 Reviewers agreed at journal 28 Feb, 2026 Reviews received at journal 27 Feb, 2026 Reviewers agreed at journal 27 Feb, 2026 Reviews received at journal 27 Feb, 2026 Reviewers agreed at journal 27 Feb, 2026 Reviews received at journal 27 Feb, 2026 Reviewers agreed at journal 27 Feb, 2026 Reviewers agreed at journal 27 Feb, 2026 Reviewers agreed at journal 27 Feb, 2026 Reviewers agreed at journal 27 Feb, 2026 Reviewers agreed at journal 27 Feb, 2026 Reviewers agreed at journal 27 Feb, 2026 Reviewers invited by journal 27 Feb, 2026 Submission checks completed at journal 04 Feb, 2026 First submitted to journal 31 Jan, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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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-8610442","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":599597699,"identity":"a5103522-f26a-49d9-8f75-66053bfc3352","order_by":0,"name":"Esraa Mohammed Mohammed Hamza","email":"data:image/png;base64,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","orcid":"","institution":"Ain Shams University","correspondingAuthor":true,"prefix":"","firstName":"Esraa","middleName":"Mohammed Mohammed","lastName":"Hamza","suffix":""},{"id":599597700,"identity":"9d06b0ef-1fe3-468f-8a54-54e38b8df70a","order_by":1,"name":"Wael Mohamed Mostafa Emam","email":"","orcid":"","institution":"Ain Shams University","correspondingAuthor":false,"prefix":"","firstName":"Wael","middleName":"Mohamed Mostafa","lastName":"Emam","suffix":""},{"id":599597701,"identity":"a09e252d-4d51-46ad-9dd2-61913d7573e4","order_by":2,"name":"Fatma Samy Sayed Hafez","email":"","orcid":"","institution":"Ain Shams University","correspondingAuthor":false,"prefix":"","firstName":"Fatma","middleName":"Samy Sayed","lastName":"Hafez","suffix":""},{"id":599597702,"identity":"d1b5bd7a-cfb7-48e8-b714-effb44331b20","order_by":3,"name":"Nehad Mohammed Osman","email":"","orcid":"","institution":"Ain Shams University","correspondingAuthor":false,"prefix":"","firstName":"Nehad","middleName":"Mohammed","lastName":"Osman","suffix":""},{"id":599597703,"identity":"ff7b8f79-ab4c-47a6-aceb-4a29a91933bf","order_by":4,"name":"Ashraf Mokhtar Madkour","email":"","orcid":"","institution":"Ain Shams University","correspondingAuthor":false,"prefix":"","firstName":"Ashraf","middleName":"Mokhtar","lastName":"Madkour","suffix":""}],"badges":[],"createdAt":"2026-01-15 12:38:28","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8610442/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8610442/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":104175842,"identity":"45e3644e-f199-4d84-841d-ab68e3e36745","added_by":"auto","created_at":"2026-03-08 16:33:04","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":769069,"visible":true,"origin":"","legend":"\u003cp\u003eRadiologic imaging of an anterior mediastinal mass infiltrating the superior vena cava.\u003c/p\u003e\n\u003cp\u003e(A) Chest computed tomography (CT) scan shows an anterior mediastinal mass infiltrating the SVC (arrow). (B) PET-CT image displays FDG uptake in the anterior mediastinal mass, highlighting its metabolic activity. (C) Another view of the chest CT, at a level inferior to that in image A, shows continued infiltration of the SVC by the anterior mediastinal mass. (D) A PET-CT Scan image shows intense FDG uptake in the mass, further indicating invasion into the SVC and right atrium (arrow).\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8610442/v1/02e53d0f23dc6a1c8fdade0e.jpeg"},{"id":104403753,"identity":"c6524bad-c474-4018-9c2f-828bb74ee554","added_by":"auto","created_at":"2026-03-11 12:18:58","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":426382,"visible":true,"origin":"","legend":"\u003cp\u003eCT image showing an increase in mediastinal mass size with contralateral pleural effusion.\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-8610442/v1/23f3d3f1bfa3099b1637b922.png"},{"id":104175839,"identity":"4bb7c1a1-a40b-4ad7-9a2a-56d12e1ee089","added_by":"auto","created_at":"2026-03-08 16:33:04","extension":"jpeg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":345017,"visible":true,"origin":"","legend":"\u003cp\u003eEBUS imaging showing 4R lymph node, SVC compression, and blood flow around the tumor.\u003c/p\u003e\n\u003cp\u003e(A) Multilobulated 4R lymph node, SVC tightly packed by the tumor mass (arrow), (B) blood stream detected around the tumor on color Doppler imaging.\u003c/p\u003e","description":"","filename":"floatimage10.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8610442/v1/1a9d0fabd7f3e64fa2d4c884.jpeg"},{"id":104175843,"identity":"38cc62ef-ad54-4ef6-9006-1b2c7c687eae","added_by":"auto","created_at":"2026-03-08 16:33:04","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":148525,"visible":true,"origin":"","legend":"\u003cp\u003eEBUS-TBNA was taken from the center of the intravascular tumor mass inside the SVC.\u003c/p\u003e","description":"","filename":"floatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-8610442/v1/6b16a2d52e81a90fc5403be8.png"},{"id":104175844,"identity":"fe9db676-7d9a-4071-ad64-6d52608d9ae2","added_by":"auto","created_at":"2026-03-08 16:33:04","extension":"jpeg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":1147287,"visible":true,"origin":"","legend":"\u003cp\u003eHistopathologic features of the primary mediastinal seminoma.\u003c/p\u003e\n\u003cp\u003eHistopathologic features of the case (A) Smear examined during ROSE reveals sheets of discohesive large neoplastic cells with scattered small lymphocytes in a bloody background (H\u0026amp;E x100). (B) Examination of the cell block revealed multiple fragments showing infiltration by large discohesive neoplastic cells in a bloody background (H\u0026amp;E x100). (C) The cells are large with moderate cytoplasm, rounded slightly irregular nuclei, one or more prominent nucleoli with a background of mature lymphocytes (H\u0026amp;E x400). (D) SALL4 immunostaining: Positive nuclear staining of neoplastic cells (IHC x400) (E) C-kit immunostaining: Positive cytoplasmic staining of neoplastic cells (IHC x400). (F) LCA immunostaining: Negative staining of neoplastic cells with positivity in the background mature reactive lymphocytes (IHC x400).\u003c/p\u003e","description":"","filename":"floatimage13.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8610442/v1/c974f62b2e3b39981aedd256.jpeg"},{"id":104409250,"identity":"18cbb364-eb2f-4f42-9a69-325bf03a75c4","added_by":"auto","created_at":"2026-03-11 12:44:29","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3540692,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8610442/v1/8365f221-0465-4b8c-9ac6-b11ef4234876.pdf"},{"id":104403961,"identity":"ad645e22-6c5d-44e6-8458-ed492e20c447","added_by":"auto","created_at":"2026-03-11 12:19:27","extension":"mp4","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":1180058,"visible":true,"origin":"","legend":"","description":"","filename":"Needlebiopsy.mp4","url":"https://assets-eu.researchsquare.com/files/rs-8610442/v1/e55f3932d32402c194dfa783.mp4"}],"financialInterests":"No competing interests reported.","formattedTitle":"Intravascular EBUS-TBNA for Diagnosis of Primary Mediastinal Seminoma Invading the Superior Vena Cava: A Case Report","fulltext":[{"header":"Introduction","content":"\u003cp\u003ePrimary mediastinal seminomas are exceedingly uncommon and were initially identified by Woolner and colleagues in 1955 (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e). Germ cell tumors comprise only 1\u0026ndash;4% of mediastinal tumors, with seminomas being the second most prevalent type after teratomas. Seminomas are slow-growing and frequently infiltrate local structures, often being substantial at the time of diagnosis (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003ePrimary mediastinal seminoma's pathogenesis remains incomplete; however, it may be associated with the retention and displacement of germ cells or pluripotent stem cells to the mediastinum, induction by carcinogenic factors, or ectopic gonadal tissue through embryonic development (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eMisdiagnosis and improper therapy are probable in the diagnosis and management of primary mediastinal seminoma. A complete diagnostic strategy is necessary, including clinical complaints, imaging studies, serum tumor markers, and validated by histology for a definitive diagnosis. (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e).\u003c/p\u003e"},{"header":"Case Presentation","content":"\u003cp\u003eA 27-year-old male presented with no prior comorbid conditions and no history of smoking or any addiction. He reported a dry cough and progressive dyspnea (grade 3, Modified Medical Research Council [mMRC]) for the past 7 months. Computed tomography (CT) imaging and whole-body positron emission tomography-computed tomography (PET-CT) were performed. The results demonstrated a heterogeneously enhancing mass with areas of breakdown, infiltrating the right upper lobe and extending to the anterior mediastinum, abutting the right atrium as well as the superior vena cava (SVC) (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e1\u003c/span\u003eA, B). The greatest dimensions were 6.5 \u0026times; 6.8 \u0026times; 7.7 cm, with a maximum standardized uptake value (SUVmax) of 14.5 (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e1\u003c/span\u003eC, D). No other mediastinal lymph nodes were enlarged.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe initial CT-guided biopsy showed necrotizing granulomas, which, in our TB-endemic setting, raised a strong clinical suspicion of tuberculosis. Empiric antituberculosis therapy was initiated. A repeated CT scan conducted four months later revealed an enlargement of the mass to 7.4 \u0026times; 7.7 \u0026times; 10.5 cm, accompanied by contralateral pleural effusion (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e2\u003c/span\u003e) despite continuous antituberculosis medication. The absence of clinical and radiological improvement after four months necessitated re-evaluation to reassess the diagnosis.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFor additional evaluation and diagnosis, he was referred to our bronchoscopy unit. Presumably, the mass was classified as a mediastinal tumor due to its invasion of the SVC and its location. To obtain tissue samples for pathological diagnosis, we elected to conduct endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA).\u003c/p\u003e \u003cp\u003eEBUS-TBNA was conducted under general anesthesia. Conventional bronchoscopy (Pentax, EB1570K) was within the normal range, apart from a submucosal protrusion at the second and third intercartilaginous spaces above the carina between 12 and 2 o'clock. The EBUS bronchoscope (Pentax, EB-19-J10U; ARIETTA V60, ALOKA, HITACHI Ltd., Tokyo, Japan) at the level of the submucosal bulge at the site of right lower paratracheal lymph node (4R LN) showed multiple oval homogeneous appearing nodal structures with well-defined distinct borders, each measuring 0.8 cm, with no intranodal vessels, or calcification. The SVC was densely encased by the intravascular homogenous tumor mass, characterized by indistinct margins and the absence of necrosis, measuring 2.1 cm (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e3\u003c/span\u003eA). Blood flow was detected around the tumor on color Doppler imaging (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e3\u003c/span\u003eB).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe tumor was punctured through a 22-gauge needle under real-time EBUS visualization, and three passes of EBUS-TBNA biopsies were successfully obtained from the intravascular mass inside the SVC (Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThroughout the procedure, careful Doppler assessment was used to confirm the vascular nature of the mass and to select a relatively avascular puncture site within the SVC, ensuring optimal safety. Real-time EBUS guidance allowed precise needle placement into the intravascular tumor while avoiding injury to the vascular wall. To further enhance safety, the EBUS scope was firmly compressed against the vessel wall immediately after each needle pass to promote hemostasis. Rapid on-site evaluation (ROSE) confirmed sample adequacy after 3 needle passes, reducing the need for additional sampling and limiting procedural trauma. The procedure was completed without significant bleeding or other complications, and the patient was closely monitored post-procedure with no adverse events observed.\u003c/p\u003e \u003cp\u003ePreliminary ROSE was done and revealed sheets of discohesive large neoplastic cells with scattered small lymphocytes in a bloody background (Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e5\u003c/span\u003eA). Tissue biopsies and slides were sent for histopathological examination. Examination of the tissue block demonstrated dispersed large atypical epithelioid/ round cells having hyperchromatic pleomorphic nuclei, coarse chromatin, and prominent nucleoli, surrounded by scattered mature reactive lymphocytes in a bloody background (Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e5\u003c/span\u003eB, C). Immunohistochemistry was performed using pan CK, SALL4, c-Kit, LCA, CD30, and glypican-3. The results revealed Positive staining of neoplastic cells to SALL4 and c-Kit. LCA showed negative staining of neoplastic cells with positivity of the reactive lymphocytes (Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e5\u003c/span\u003eD, E, F). Pan CK, CD30, and glypican-3 were negative. These results led to a definitive diagnosis of mediastinal seminoma.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eEBUS-TBNA is a minimally invasive method used to examine lymph nodes in the mediastinum while providing real-time imaging of thoracic structures (7). EBUS-TBNA capability to detect abnormalities within mediastinal blood vessels, such as tumors or clots, has raised questions about whether these lesions can be safely sampled, particularly in patients for whom conventional surgical approaches are risky or unsuitable (\u003cspan class=\"CitationRef\"\u003e8\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIn our case, EBUS-TBNA enabled us to obtain tissue from the intravascular mass inside the SVC without significant adverse events, avoiding the need for an undesirable thoracotomy under general anesthesia. The final histopathological diagnosis revealed mediastinal seminoma.\u003c/p\u003e \u003cp\u003eA review of the literature highlights the rarity of primary mediastinal seminomas, with most diagnoses historically achieved via surgical or percutaneous biopsy [Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e]. Li et al. and Petrova et al. reported individual cases diagnosed through needle and CT-guided approaches, while Napieralska et al. described a broader series spanning three decades (\u003cspan class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e9\u003c/span\u003e). Notably, Zhang et al. reported successful diagnosis of a primary mediastinal seminoma through transbronchial mediastinal cryobiopsy, highlighting the ability of an EBUS-guided approach for the cryobiopsy to yield adequate tissue without surgical intervention(\u003cspan class=\"CitationRef\"\u003e10\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eMeanwhile, the application of EBUS-TBNA for transvascular and intravascular sampling has been increasingly recognized as a safe and effective diagnostic approach [Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e]. Notably, Lee et al. successfully performed intravascular EBUS-TBNA on a tumor within the SVC, closely mirroring our case (\u003cspan class=\"CitationRef\"\u003e7\u003c/span\u003e). Further evidence is provided by Harris et al. and Panchabhai et al., who collectively reported multiple transvascular and intravascular EBUS-TBNA cases with excellent safety profiles (\u003cspan class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e11\u003c/span\u003e). Together, these reports emphasize the expanding role of EBUS-TBNA in the diagnosis of complex vascular tumors.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\"\u003e\u003c/div\u003e\u003ctable id=\"Tab1\" border=\"1\"\u003e \u003ccaption\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003e(\u003cb\u003eExpanded Literature Review)\u003c/b\u003e\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003c/colgroup\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\"\u003e \u003cp\u003eAuthor (Year)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003eCondition/Diagnosis\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003eBiopsy Method\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003eVascular Involvement\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003eAdverse events\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003eKey Findings\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eLi and co-authors (2024) (\u003cspan class=\"CitationRef\"\u003e9\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003ePrimary Mediastinal Seminoma with Azoospermia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eNeedle Biopsy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eNot specified\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eNone\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eSingle case diagnosed via needle biopsy; highlighted azoospermia association.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eNapieralska and co-authors (2018) (\u003cspan class=\"CitationRef\"\u003e2\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003ePrimary Mediastinal Seminoma\u003c/p\u003e \u003cp\u003e(16 cases)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003e16 cases over 31 years; 6 diagnosed incidentally post-surgery\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eSuperior vena cava syndrome occurred in 19% of patients\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eNot specified\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eFocused primarily on treatment and clinical outcomes\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\"\u003e \u003cp\u003ePetrova and co-authors (2019) (\u003cspan class=\"CitationRef\"\u003e3\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003ePrimary Mediastinal Seminoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eCT-Guided Biopsy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eNot specified\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eNone\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eSingle case; diagnosed with the presence of bilateral effusions\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eZhang and co-authors (2020) (\u003cspan class=\"CitationRef\"\u003e10\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003ePrimary Mediastinal Seminoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eEBUS guided Transbronchial mediastinal cryobiopsy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eNot specified\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eslight bleeding\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eEBUS–guided transbronchial mediastinal cryobiopsy is an effective approach for obtaining sufficient tissue biopsies\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eLee and co-authors (2016) (\u003cspan class=\"CitationRef\"\u003e7\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eLung Cancer with SVC Syndrome\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eIntravascular EBUS-TBNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eSuperior Vena Cava\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eNone\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eDemonstrated safety and efficacy of intravascular EBUS-TBNA for diagnosis.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eHarris and co-authors (2015) (\u003cspan class=\"CitationRef\"\u003e8\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eIntravascular and transvascular lesions\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eIntravascular and transvascular EBUS-TBNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003ePulmonary Artery, descending aorta\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eNone\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eSystematic review of multiple cases; safe and successful tissue acquisition.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\"\u003e \u003cp\u003ePanchabhai and co-authors (2015) (\u003cspan class=\"CitationRef\"\u003e11\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eTransvascular Lesions\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eTransvascular EBUS-TBNA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003ePulmonary artery and its branches.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eNone\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eSingle-center experience of 10 cases;\u003c/p\u003e \u003cp\u003eNo adverse events reported.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/table\u003e\u003c/div\u003e \u003cp\u003e\u003c/p\u003e \u003cp\u003eSimilarly, in our case, EBUS-TBNA was successfully utilized to puncture the SVC without any adverse events. Building on previous reports and our experience, this case highlights that, when performed by skilled operators, intravascular and transvascular sampling through EBUS-TBNA can be considered a safe and effective approach.\u003c/p\u003e\n\u003ch3\u003eLimitations\u003c/h3\u003e\n\u003cp\u003eThis case report is limited by its single-patient design, which restricts the ability to generalize the findings to broader patient populations. Additionally, while EBUS-TBNA was performed safely in this instance, further cases are needed to validate its safety and diagnostic reliability for intravascular tumors.\u003c/p\u003e \u003cp\u003e\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThis case reinforces the expanding role of EBUS-TBNA as a safe, effective, and minimally invasive technique for diagnosing challenging intravascular mediastinal tumors. Our successful diagnosis of a rare mediastinal seminoma through intravascular biopsy highlights the procedure’s potential to access complex lesions previously considered difficult to sample without resorting to high-risk surgical approaches.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eEBUS-TBNA\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eEndobronchial Ultrasound-Guided Transbronchial Needle Aspiration\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eSVC\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eSuperior Vena Cava\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eCT\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eComputed Tomography\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003ePET-CT\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePositron Emission Tomography - Computed Tomography\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eSUVmax\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eMaximum Standardized Uptake Value\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eROSE\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eRapid On-Site Evaluation\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003emMRC\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eModified Medical Research Council (Dyspnea Scale).\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":" \u003cp\u003e\u003cb\u003eEthical Approval and Informed Consent\u003c/b\u003e: Ethical approval for this case report was granted by the Ethical Committee of Ain Shams University. In addition, written informed consent was obtained from the patient for the publication of this report.\u003c/p\u003e \u003cp\u003e \u003cstrong\u003eAvaliability of data\u003c/strong\u003e \u003cp\u003eNo data was produced or assessed in the course of this case report.\u003c/p\u003e \u003cp\u003e \u003cstrong\u003eCompeting interests:\u003c/strong\u003e \u003cp\u003eThe authors have no competing interests to disclose.\u003c/p\u003e \u003ch2\u003eFunding:\u003c/h2\u003e \u003cp\u003eThis work was completed without any financial funding related to research, authorship, or publication.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eAshraf Madkour: Conceptualization, supervision, critical revision of the manuscript, and final approval of the version to be published, Nehad Osman: Supervision, substantial contributions to clinical management, critical review of the manuscript, and final approval, Wael Emam: Case data collection, detailed literature review, clinical data analysis and editing, Esraa Hamza: Major contribution to manuscript writing, literature analysis, preparation of clinical figures, and substantial input in case discussion, Fatma Hafez: Histopathological examination, preparation and interpretation of pathology slides and images, contribution to the pathology discussion, and critical revision of pathology content.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eWoolner LB, Jamplis RW, Kirklin JW (1955) Seminoma (germinoma) apparently primary in the anterior mediastinum. N Engl J Med 252(16):653\u0026ndash;657\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNapieralska A, Majewski W, Osewski W, Miszczyk L (2018) Primary mediastinal seminoma. J Thorac Dis 10(7):4335\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePetrova D, Kraleva S, Muratovska L, Crcareva B (2019) Primary seminoma localized in mediastinum: case report. Open Access Maced J Med Sci 7(3):384\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eXiu W, Pang J, Hu Y, Shi H (2023) Immune-related mechanisms and immunotherapy in extragonadal germ cell tumors. Front Immunol 14:1145788\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGuida E, Tassinari V, Colopi A, Todaro F, Cesarini V, Jannini B et al (2022) MAPK activation drives male and female mouse teratocarcinomas from late primordial germ cells. J Cell Sci 135(8):jcs259375\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCommittee ACPR (2022) S Cancer in 2022. Cancer Discov. 2022;12(12):2733\u0026ndash;8\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLee D, Moon SM, Kim D, Kim J, Chang H, Yang B et al (2016) Lung cancer with superior vena cava syndrome diagnosed by intravascular biopsy through EBUS-TBNA. Respir Med Case Rep 19:177\u0026ndash;180\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHarris K, Modi K, Kumar A, Dhillon SS (2015) Endobronchial ultrasound-guided transbronchial needle aspiration of pulmonary artery tumors: A systematic review (with video). Endosc Ultrasound 4(3):191\u0026ndash;197\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi Z, Zhu Q, Niu S, Xiao K, Xiao Z, Yang P (2024) Primary mediastinal seminoma with azoospermia: case report and review of the literature. Front Oncol 14:1309803\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang J, Fu WL, Huang ZS, Guo JR, Li Q, Herth FJF et al (2020) Primary mediastinal seminoma achieved by transbronchial mediastinal cryobiopsy. Respiration 99(5):426\u0026ndash;430\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePanchabhai TS, Machuzak MS, Sethi S, Vijhani P, Gildea TR, Mehta AC et al (2015) Endobronchial Ultrasound\u0026ndash;guided Transvascular Needle Aspiration: A Single-Center Experience. J Bronchol Interv Pulmonol 22(4):306\u0026ndash;311\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"the-egyptian-journal-of-bronchology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"Learn more about [The Egyptian Journal of Bronchology](https://ejb.springeropen.com/)","snPcode":"43168","submissionUrl":"https://submission.nature.com/new-submission/43168/3","title":"The Egyptian Journal of Bronchology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Open","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Endobronchial ultrasound, Biopsy, Fine-Needle, Mediastinal Neoplasms, Seminoma, Vascular Neoplasms","lastPublishedDoi":"10.21203/rs.3.rs-8610442/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8610442/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eMediastinal seminoma is a very rare extragonadal malignant germ cell tumor often misdiagnosed.\u003c/p\u003e\u003ch2\u003eCase presentation:\u003c/h2\u003e \u003cp\u003eA 27-year-old male presented with dyspnea. Imaging exhibited a mass invading the right upper lobe and extending to the anterior mediastinum and invading the superior vena cava (SVC). CT-guided biopsy showed necrotizing granulomas, and empiric antituberculosis therapy was initiated. The absence of clinical and radiological improvement after four months necessitated re-evaluation via EBUS-TBNA to reassess the diagnosis. EBUS-TBNA from the mass invading SVC through intravascular approach was performed without significant adverse events and yielded adequate tissue, with rapid on-site assessment and histopathology confirmed seminoma.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eIntravascular EBUS-TBNA is a safe, minimally invasive technique for diagnosing primary mediastinal Seminoma invading the SVC.\u003c/p\u003e","manuscriptTitle":"Intravascular EBUS-TBNA for Diagnosis of Primary Mediastinal Seminoma Invading the Superior Vena Cava: A Case Report","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-03-08 16:32:59","doi":"10.21203/rs.3.rs-8610442/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision 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