Congenital Midureteric Stenosis Mimicking Ureteropelvic Junction Obstruction: A Rare Cause of Pediatric Hydronephrosis

Congenital Midureteric Stenosis Mimicking Ureteropelvic Junction Obstruction: A Rare Cause of Pediatric Hydronephrosis | 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 Congenital Midureteric Stenosis Mimicking Ureteropelvic Junction Obstruction: A Rare Cause of Pediatric Hydronephrosis Mehmet Taşdemir, Omar Habboub, Hüseyin Murat Mutuş, Maimona Weisy, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7181806/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background: Hydronephrosis resulting from ureteropelvic junction obstruction, the most common cause of obstructive uropathy in children, can also be caused by the rare anomaly, congenital midureteric stenosis. This case highlights the diagnostic challenge of congenital midureteric stenosis, which can clinically and radiographically mimic ureteropelvic junction obstruction. Case Presentation: We report a 5-month-old infant boy presenting with right-sided grade 3 hydronephrosis. Magnetic resonance urography and retrograde pyelography confirmed the diagnosis of congenital midureteric stenosis. At eleven months, definitive surgical correction via dismembered ureteroureterostomy was performed. Conclusions: Magnetic resonance urography can be an initial diagnostic tool to confirm Congenital midureteric stenosis along with the use of retrograde pyelography as needed. Congenital midureteric stenosis hydronephrosis ureteroureterostomy pediatrics pediatric urology Figures Figure 1 Background Congenital midureteric stenosis (CMUS) is a rare cause of ureteral obstruction in the pediatric population and is commonly overshadowed by ureteropelvic junction obstruction (UPJO) and megaureter [ 1 ]. CMUS has been seen in only 4–5% of ureteral obstructions in children [ 2 ]. It poses a diagnostic challenge due to its clinical and radiological similarity to UPJO. Accurate identification is essential, especially for surgical planning, as delayed or incorrect diagnosis can lead to progressive kidney damage. This case involves an infant boy presenting with hydronephrosis. Magnetic resonance (MR) urography suggested midureteric stenosis and was confirmed with retrograde pyelography. The case highlights considering CMUS in the differential diagnosis of pediatric hydronephrosis while also emphasizing the role of MR urography and retrograde pyelography in accurate diagnosis and surgical planning. Case presentation A five-month-old male infant admitted to our clinic with the diagnosis of right-sided grade 3 hydronephrosis in the 24th gestational week. Ultrasonography (US) revealed a small, hyperechoic right kidney, suggestive of a hypoplastic-dysplastic kidney, with a parenchymal thickness of 7.5 mm and a renal pelvic anterior-posterior (AP) diameter of 15.5 mm. The left kidney appeared normal. A technetium-99m mercaptoacetyltriglycine (Tc-99m MAG3) renogram indicated impaired extraction and excretion in the right kidney. At 8.5 months of age, due to persistent right-sided hydronephrosis, observed in repeated US examinations, along with a fusiform dilatation of the proximal ureter measuring up to 15 mm in diameter and extending approximately 40 mm in length, MR urography was performed to further characterize the anatomy and evaluate the underlying cause. It demonstrated proximal right ureteral dilatation terminating abruptly at the mid-ureter level (Fig. 1 a and 1 b). Retrograde pyelography confirmed the diagnosis of CMUS, and double-J stenting was performed. Although hydronephrosis initially decreased, it worsened following stent removal. Definitive surgical correction via dismembered ureteroureterostomy, was performed at 11 months of age in which clear CMUS could be observed (Fig. 1 c). Histopathological examination of the excised segment revealed no intrinsic abnormalities. Over a three-year postoperative follow-up, the patient remained clinically stable without urinary tract infections. The most recent US showed a reduced hydronephrosis degree in the right kidney and normal pelvic appearance (Fig. 1 d). Discussion and Conclusions CMUS, which usually presents unilaterally, is very uncommonly seen within the causes of congenital ureteral obstructive conditions in pediatrics [ 3 ]. Although multiple theories were presented, three major theories for explaining this anomaly are failure of recanalization of the developing ureter, vascular compression in utero and acquired fetal inflammation of the ureter [ 4 ]. Hydronephrosis is the most common presentation in CMUS [ 3 ]. Due to the overlaps, CMUS is initially diagnosed as more frequent conditions, such as UPJO and megaureter [ 1 ]. Ultrasound examination may not always localize the exact reason or length of obstruction [ 4 ], but can show initial findings, and can be useful as a primary source of information before continuing with alternative imaging techniques [ 3 ]. MR urography imaging gives a distinct advantage in observing ureteric abnormalities and can diagnose stenosis in the ureters before any surgical intervention [ 5 ]. It should be noted that in complex cases of CMUS combined with other UPJOs, retrograde pyelography is highly beneficial, as it is commonly used to confirm CMUS in postnatal stages [ 2 ]. Retrograde pyelography is indicated in cases of suspected CMUS as it will show the anatomy more clearly [ 4 ], accurately revealing the site of obstruction. A double-J stent can passively dilate stenosis in ureters in cases such as CMUS [ 5 ]. Double-J stenting also prepares the environment for retrograde pyelography to confirm diagnosis [ 5 ]. As in our case, double-J stenting aided in decompression when the infant was eleven months old and a dismembered ureteroureterostomy was performed, it being the common procedure for such cases [ 1 , 4 ]. Post operatively, as healing progresses, the stent can be removed, and follow-up can be done using US [ 2 , 5 ]. CMUS can be misdiagnosed as UPJO, both clinically and radiographically. Misdiagnosis may delay the use of appropriate imaging modalities, potentially leading to late or incorrect treatment. PostnatalMR urography and retrograde pyelography areessential tools for accurate diagnosis and surgical planning, especially in complicated cases. Timely surgical intervention may preserve renal function, even in the presence of a hypoplastic-dysplastic kidney. Abbreviations CMUS congenital midureteric stenosis UPJO ureteropelvic junction obstruction MR magnetic resonance US ultrasonography AP anterior-posterior Tc-99m MAG3 technetium-99m mercaptoacetyltriglycine Declarations Ethics approval and consent to participate: Not applicable Consent for publication: Written informed consent was obtained from the patient’s parents for publication of this case report and accompanying images. Availability of data and materials: Not applicable Competing Interests: The authors declare that they have no competing interests Clinical trial number: not applicable. Funding: None Author’s Contributions: MT made substantial contributions to the clinical management of the case, drafting of the case section, organization of the manuscript, interpretation of data, and final critical revision. OH contributed to the literature review and drafting of the manuscript. HMM was involved in the clinical follow-up and contributed to writing the case section. MW contributed to the acquisition and interpretation of data through literature review and participated in drafting the manuscript. OO substantively revised the manuscript and contributed to its final editing. SS was responsible for the surgical management and follow-up of the case, contributed to the literature review, and participated in the substantive revision and final editing of the manuscript. All authors read and approved the final version of the manuscript. Acknowledgments: We sincerely thank the patient’s family for providing their consent and support for the publication of this case report. References Paludo A, de O, Diaz JO, Menegola C, Cavaleri A, Gorgen ARH, Lucena IRS, et al. J Pediatr Urol. 2020;16:859–60. https://doi.org/10.1016/j.jpurol.2020.10.022 . Chu H, Deng Q, Cao Y, Asian. J Surg. 2025;48:2212–3. https://doi.org/10.1016/j.asjsur.2024.10.014 . Domenichelli V, De Biagi L, Italiano F, Carfagnini F, Lavacchini A, Federici S. 2008;4:401–3. https://doi.org/10.1016/j.jpurol.2008.01.214 Jayanthi VR, Churchill BM, Thorner PS, McLORIE GA, Khoury AE. Urology. 1995;45:673–6. https://doi.org/10.1016/S0090-4295(99)80028-4 . Grattan-Smith JD, Jones RA, Little S, Kirsch AJ. Pediatr Radiol. 2011;41:117–20. https://doi.org/10.1007/s00247-010-1799-z . Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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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-7181806","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":496844328,"identity":"d5bd2a32-8cc8-4a41-92ce-be666eb994f9","order_by":0,"name":"Mehmet Taşdemir","email":"data:image/png;base64,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","orcid":"","institution":"Istinye University","correspondingAuthor":true,"prefix":"","firstName":"Mehmet","middleName":"","lastName":"Taşdemir","suffix":""},{"id":496844330,"identity":"ef0ae42c-92f4-400f-8038-46f1c9bfc62e","order_by":1,"name":"Omar Habboub","email":"","orcid":"","institution":"Istinye University","correspondingAuthor":false,"prefix":"","firstName":"Omar","middleName":"","lastName":"Habboub","suffix":""},{"id":496844332,"identity":"38cf16d0-0f44-448d-81d8-d76c1c124d36","order_by":2,"name":"Hüseyin Murat Mutuş","email":"","orcid":"","institution":"Istinye University","correspondingAuthor":false,"prefix":"","firstName":"Hüseyin","middleName":"Murat","lastName":"Mutuş","suffix":""},{"id":496844333,"identity":"1ad7dcbe-65df-41c5-b53f-ece4e0c06648","order_by":3,"name":"Maimona Weisy","email":"","orcid":"","institution":"Istinye University","correspondingAuthor":false,"prefix":"","firstName":"Maimona","middleName":"","lastName":"Weisy","suffix":""},{"id":496844334,"identity":"a94f6348-4cab-4f1d-b5e8-45282d65beef","order_by":4,"name":"Ozan Özkaya","email":"","orcid":"","institution":"Istinye University","correspondingAuthor":false,"prefix":"","firstName":"Ozan","middleName":"","lastName":"Özkaya","suffix":""},{"id":496844339,"identity":"4d00dd18-696d-4850-b7c6-52bee73faad4","order_by":5,"name":"Selami Sözübir","email":"","orcid":"","institution":"Istinye University","correspondingAuthor":false,"prefix":"","firstName":"Selami","middleName":"","lastName":"Sözübir","suffix":""}],"badges":[],"createdAt":"2025-07-22 02:38:21","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7181806/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7181806/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":88643793,"identity":"92354204-6b93-499c-8e40-f23d728147d2","added_by":"auto","created_at":"2025-08-08 16:17:48","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":3489281,"visible":true,"origin":"","legend":"\u003cp\u003eRepresentative images from the diagnostic and follow-up process: (a) preoperative magnetic resonance urography showing right sided hydroureteronephrosis; (b) ultrasound image of the right kidney demonstrating preoperative hydronephrosis; (c) intraoperative view revealing midureteric stenosis; and (d) postoperative ultrasound indicating normalization of the renal pelvis.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-7181806/v1/e72483a4409e9effc7860e4f.png"},{"id":92420317,"identity":"bb005b8e-427a-4460-8b4c-fb8c7bd9211b","added_by":"auto","created_at":"2025-09-29 14:16:34","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3276172,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7181806/v1/7a71bf90-9bc8-4ae7-aa2d-ef29c675e105.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Congenital Midureteric Stenosis Mimicking Ureteropelvic Junction Obstruction: A Rare Cause of Pediatric Hydronephrosis","fulltext":[{"header":"Background","content":"\u003cp\u003eCongenital midureteric stenosis (CMUS) is a rare cause of ureteral obstruction in the pediatric population and is commonly overshadowed by ureteropelvic junction obstruction (UPJO) and megaureter [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. CMUS has been seen in only 4–5% of ureteral obstructions in children [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. It poses a diagnostic challenge due to its clinical and radiological similarity to UPJO. Accurate identification is essential, especially for surgical planning, as delayed or incorrect diagnosis can lead to progressive kidney damage.\u003c/p\u003e\u003cp\u003eThis case involves an infant boy presenting with hydronephrosis. Magnetic resonance (MR) urography suggested midureteric stenosis and was confirmed with retrograde pyelography. The case highlights considering CMUS in the differential diagnosis of pediatric hydronephrosis while also emphasizing the role of MR urography and retrograde pyelography in accurate diagnosis and surgical planning.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"Case presentation","content":"\u003cp\u003eA five-month-old male infant admitted to our clinic with the diagnosis of right-sided grade 3 hydronephrosis in the 24th gestational week. Ultrasonography (US) revealed a small, hyperechoic right kidney, suggestive of a hypoplastic-dysplastic kidney, with a parenchymal thickness of 7.5 mm and a renal pelvic anterior-posterior (AP) diameter of 15.5 mm. The left kidney appeared normal. A technetium-99m mercaptoacetyltriglycine (Tc-99m MAG3) renogram indicated impaired extraction and excretion in the right kidney. At 8.5 months of age, due to persistent right-sided hydronephrosis, observed in repeated US examinations, along with a fusiform dilatation of the proximal ureter measuring up to 15 mm in diameter and extending approximately 40 mm in length, MR urography was performed to further characterize the anatomy and evaluate the underlying cause. It demonstrated proximal right ureteral dilatation terminating abruptly at the mid-ureter level (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea and \u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eb). Retrograde pyelography confirmed the diagnosis of CMUS, and double-J stenting was performed. Although hydronephrosis initially decreased, it worsened following stent removal. Definitive surgical correction via dismembered ureteroureterostomy, was performed at 11 months of age in which clear CMUS could be observed (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ec). Histopathological examination of the excised segment revealed no intrinsic abnormalities. Over a three-year postoperative follow-up, the patient remained clinically stable without urinary tract infections. The most recent US showed a reduced hydronephrosis degree in the right kidney and normal pelvic appearance (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ed).\u003c/p\u003e"},{"header":"Discussion and Conclusions","content":"\u003cp\u003eCMUS, which usually presents unilaterally, is very uncommonly seen within the causes of congenital ureteral obstructive conditions in pediatrics [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Although multiple theories were presented, three major theories for explaining this anomaly are failure of recanalization of the developing ureter, vascular compression in utero and acquired fetal inflammation of the ureter [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eHydronephrosis is the most common presentation in CMUS [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Due to the overlaps, CMUS is initially diagnosed as more frequent conditions, such as UPJO and megaureter [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Ultrasound examination may not always localize the exact reason or length of obstruction [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e], but can show initial findings, and can be useful as a primary source of information before continuing with alternative imaging techniques [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. MR urography imaging gives a distinct advantage in observing ureteric abnormalities and can diagnose stenosis in the ureters before any surgical intervention [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eIt should be noted that in complex cases of CMUS combined with other UPJOs, retrograde pyelography is highly beneficial, as it is commonly used to confirm CMUS in postnatal stages [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Retrograde pyelography is indicated in cases of suspected CMUS as it will show the anatomy more clearly [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e], accurately revealing the site of obstruction.\u003c/p\u003e\u003cp\u003eA double-J stent can passively dilate stenosis in ureters in cases such as CMUS [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Double-J stenting also prepares the environment for retrograde pyelography to confirm diagnosis [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. As in our case, double-J stenting aided in decompression when the infant was eleven months old and a dismembered ureteroureterostomy was performed, it being the common procedure for such cases [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Post operatively, as healing progresses, the stent can be removed, and follow-up can be done using US [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e\n\u003cp\u003eCMUS can be misdiagnosed as UPJO, both clinically and radiographically. Misdiagnosis may delay the use of appropriate imaging modalities, potentially leading to late or incorrect treatment. PostnatalMR urography and retrograde pyelography areessential tools for accurate diagnosis and surgical planning, especially in complicated cases. Timely surgical intervention may preserve renal function, even in the presence of a hypoplastic-dysplastic kidney.\u003c/p\u003e\n"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eCMUS\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003econgenital midureteric stenosis\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eUPJO\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eureteropelvic junction obstruction\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eMR\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003emagnetic resonance\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eUS\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eultrasonography\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eAP\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eanterior-posterior\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eTc-99m MAG3\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003etechnetium-99m mercaptoacetyltriglycine\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003eEthics approval and consent to participate: Not applicable\u003c/p\u003e\n\u003cp\u003eConsent for publication: Written informed consent was obtained from the patient’s parents for publication of this case report and accompanying images.\u003c/p\u003e\n\u003cp\u003eAvailability of data and materials: Not applicable\u003c/p\u003e\n\u003cp\u003eCompeting Interests: The authors declare that they have no competing interests\u003c/p\u003e\n\u003cp\u003eClinical trial number: not applicable.\u003c/p\u003e\n\u003cp\u003eFunding: None\u003c/p\u003e\n\u003cp\u003eAuthor’s Contributions: MT made substantial contributions to the clinical management of the case, drafting of the case section, organization of the manuscript, interpretation of data, and final critical revision.\u003c/p\u003e\n\u003cp\u003eOH contributed to the literature review and drafting of the manuscript.\u003c/p\u003e\n\u003cp\u003eHMM was involved in the clinical follow-up and contributed to writing the case section.\u003c/p\u003e\n\u003cp\u003eMW contributed to the acquisition and interpretation of data through literature review and participated in drafting the manuscript.\u003c/p\u003e\n\u003cp\u003eOO substantively revised the manuscript and contributed to its final editing.\u003c/p\u003e\n\u003cp\u003eSS was responsible for the surgical management and follow-up of the case, contributed to the literature review, and participated in the substantive revision and final editing of the manuscript.\u003c/p\u003e\n\u003cp\u003eAll authors read and approved the final version of the manuscript.\u003c/p\u003e\n\u003cp\u003eAcknowledgments: We sincerely thank the patient’s family for providing their consent and support for the publication of this case report.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003ePaludo A, de O, Diaz JO, Menegola C, Cavaleri A, Gorgen ARH, Lucena IRS, et al. J Pediatr Urol. 2020;16:859\u0026ndash;60. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jpurol.2020.10.022\u003c/span\u003e\u003cspan address=\"10.1016/j.jpurol.2020.10.022\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChu H, Deng Q, Cao Y, Asian. J Surg. 2025;48:2212\u0026ndash;3. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.asjsur.2024.10.014\u003c/span\u003e\u003cspan address=\"10.1016/j.asjsur.2024.10.014\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDomenichelli V, De Biagi L, Italiano F, Carfagnini F, Lavacchini A, Federici S. 2008;4:401\u0026ndash;3. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jpurol.2008.01.214\u003c/span\u003e\u003cspan address=\"10.1016/j.jpurol.2008.01.214\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJayanthi VR, Churchill BM, Thorner PS, McLORIE GA, Khoury AE. Urology. 1995;45:673\u0026ndash;6. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/S0090-4295(99)80028-4\u003c/span\u003e\u003cspan address=\"10.1016/S0090-4295(99)80028-4\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGrattan-Smith JD, Jones RA, Little S, Kirsch AJ. Pediatr Radiol. 2011;41:117\u0026ndash;20. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s00247-010-1799-z\u003c/span\u003e\u003cspan address=\"10.1007/s00247-010-1799-z\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"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":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Congenital midureteric stenosis, hydronephrosis, ureteroureterostomy, pediatrics, pediatric urology","lastPublishedDoi":"10.21203/rs.3.rs-7181806/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7181806/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground:\u003c/strong\u003e Hydronephrosis resulting from ureteropelvic junction obstruction, the most common cause of obstructive uropathy in children, can also be caused by the rare anomaly, congenital midureteric stenosis. This case highlights the diagnostic challenge of congenital midureteric stenosis, which can clinically and radiographically mimic ureteropelvic junction obstruction.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCase Presentation:\u003c/strong\u003e We report a 5-month-old infant boy presenting with right-sided grade 3 hydronephrosis. Magnetic resonance urography and retrograde pyelography confirmed the diagnosis of congenital midureteric stenosis. At eleven months, definitive surgical correction via dismembered ureteroureterostomy was performed.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions: \u003c/strong\u003eMagnetic resonance urography can be an initial diagnostic tool to confirm Congenital midureteric stenosis along with the use of retrograde pyelography as needed.\u003c/p\u003e","manuscriptTitle":"Congenital Midureteric Stenosis Mimicking Ureteropelvic Junction Obstruction: A Rare Cause of Pediatric Hydronephrosis","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-08 16:17:43","doi":"10.21203/rs.3.rs-7181806/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"bc28f033-e044-4717-84f9-955922151102","owner":[],"postedDate":"August 8th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-09-29T14:08:20+00:00","versionOfRecord":[],"versionCreatedAt":"2025-08-08 16:17:43","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7181806","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7181806","identity":"rs-7181806","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}