A rare case of Fetal bilateral Wilms’ Tumor in horseshoe Kidney: A case report

A rare case of Fetal bilateral Wilms’ Tumor in horseshoe Kidney: 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 A rare case of Fetal bilateral Wilms’ Tumor in horseshoe Kidney: A case report Abebe Melis, Teketel Tadesse, Samson Jemal, Worku Ketema This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5766165/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 Wilms' tumor is the most common malignant kidney tumor in children. The horseshoe kidney is the most common renal fusion malformation. However, Wilms' tumor is rarely identified in horseshoe kidney patients. The incidence of horseshoe kidney is about 1 in 400 cases. Wilms’ tumor or Nephrogenic rests can occur in both kidneys, termed bilateral disease, found in only 5–8% of cases. Management of bilateral Wilms’ tumor presents a major clinical challenge in terms of maximizing survival, preserving renal function, and understanding underlying genetic risk. Ultrasound is used to diagnose horseshoe kidneys, whereas Computed tomography and magnetic resonance imaging are often used for staging purposes. Here, we present an extremely rare case of a fetus with a prenatal diagnosis of renal mass, and an autopsy found out to be a bilateral congenital Wilms’ tumor in the horseshoe kidney. Up to our knowledge, it is the first case to be reported from Ethiopia, and there are only a few case reports worldwide. Fetal Bilateral Wilms’ tumor Horseshoe kidney case report Figures Figure 1 Figure 2 Introduction Nephroblastoma, also known as Wilms' tumor (WT), is the most commonly detected pediatric malignant renal mass, accounting for 87% of all malignant renal masses and 7% of all malignant tumors found in children. 1 , 2 . The tumor is associated with undifferentiated embryonic lesions called nephrogenic rests (NRs) or, when diffuse, nephroblastomatosis. WT or NRs can occur in both kidneys, termed bilateral disease, found in only 5–8% of cases 3 . Bilateral disease can be synchronous (both kidneys affected at the same time) or metachronous (one affected after the other), which occurs in 6.3 and 0.85% WT patients respectively 4 .The median age at which this tumor is diagnosed is three years. 5 . Prenatal detection of Wilms tumor is extremely rare. Prenatal ultrasonography and fetal magnetic resonance imaging (MRI) has been found to be helpful in diagnosis of renal masses 6 . Wilms' tumor is linked to several syndromes, such as WAGR syndrome (Wilms' tumor, aniridia, genitourinary abnormalities, and spectrum of developmental delays), Beckwith-Wiedemann syndrome, Denys-Drash syndrome, and Edwards or Perlman syndrome. 7 . Some cases are associated with prenatal polyhydramnios and fetal hydrops 8 , 9 .Horseshoe kidney occurs in around 1 in 500 instances, with a higher incidence in males 10 . Nevertheless, the presence of Wilms' tumor in horseshoe kidney is very uncommon, with an estimated occurrence rate of roughly 0.4–0.9% of all Wilms' tumors. 11 . Case Presentation Our case is a 28-year-old primigravid female patient from the Sidama region, Ethiopia, who came for the complaint of decreased abdominal girth and decreased fetal moment. Other prenatal history was unremarkable. On physical examination, her vital signs were all normal. Abdominal examination revealed 18-week sized gravid uterus. On laboratory tests: Work-up for complete blood count, liver and renal function tests were within the normal range. Her blood group and Rh were AB negative. Obstetric Ultrasound: Singleton intra-uterine pregnancy, alive with Biparietal diameter (BPD)measuring 22 + 3, Femoral length (FL) 22 + 6, Abdominal circumference (AC): 31 weeks. There is 8x7 cm measuring abdominopelvic mass, abdominal contents are pushed peripherally by the mass. Placenta fundal with no measurable liquor. Index: Severe oligohydramnios + with renal mass secondary to? Nephroblastoma top on the list. Hence, safe termination was decided for the indication of incompatible congenital defects based on the existing trends. We put her on maintenance fluid with Normal saline and safe medical termination was done. Sample from fetus and products of conceptus were sent for histopathologic examination. Subsequent examinations of the autopsy revealed a bilaterally enlarged kidneys with fused lower pole with cut surface revealing multicystic spaces effacing the renal parenchyma (Fig. 1 ). Microscopic examination shows triphasic proliferation of blastemal, epithelial and stromal components which is consistent with Wilm’s tumor (Fig. 2 ) The mother had a smooth post-treatment course and was discharged on the 2nd day with oral antibiotics and advice for subsequent follow-ups and pregnancy Discussion During the fetal period, the kidneys develop and ascend, developing first in the pelvis and then gradually ascending into position below the thorax, on either side of the lumbar spine. During this ascending process, the kidneys also rotate, which typically occurs by the gestational ninth week 12 . Renal fusion anomalies may occur during this process 13 . The isthmus of the horseshoe kidney may contain functioning renal parenchyma or a fibrous band 14 . In up to 80% of cases of horseshoe kidney, the isthmus contains functional renal parenchyma tissue, and in > 90% of cases, fusion occurs at the lower pole 12 . Patients with horseshoe kidney are often asymptomatic and are typically discovered incidentally, often due to symptoms secondary to pelvic ureteric junction obstruction and infection 15 . These patients are thought to be at increased risk of developing malignancies, such as renal cell carcinoma, Wilms' tumor, and carcinoids, among which renal cell carcinoma is the most common 13 . However, Wilms' tumor is the most common malignant kidney tumor identified in children 16 . The risk of Wilms' tumor in children with horseshoe kidney is 2–6 times that of children in the general population 17 . Approximately 50% of Wilms' tumors in horseshoe kidney develop from the isthmus, likely due to the abnormal proliferation of metanephric blastema in the isthmus 13 . The same anomaly that causes the development of horseshoe kidney may also lead to the development of Wilms' tumor 18 . Patients with Wilms' tumors are often asymptomatic; approximately 10% are discovered incidentally after trauma, whereas 25% present with microscopic hematuria or hypertension secondary to renin production 19 . Ultrasound is used to diagnose horseshoe kidney, whereas Computed tomography (CT) and magnetic resonance imaging (MRI) are often used for staging purposes 20 . On ultrasound, the mass presents as a large renal mass, which can be either solid or cystic, with large hypoechoic areas due to central necrosis and cyst formation. Areas characterized by fat deposits, calcification, or hemorrhage may appear 19 . On CT, the tumors are lower density and enhance less than the normal renal parenchyma. Tumors are often characterized by heterogeneous contrast enhancement and may feature punctuated calcifications 21 . On MRI, the tumors have low signal intensity on T1-weighted images, with either low or high signal intensity on T2-weighted images and restricted diffusivity on diffusion-weighted images. CT is also used for the detection of lung metastasis or local recurrence 19 . Wilms' tumors contain variable quantities of embryonic renal elements, such as blastema, epithelium, and stroma 22 . Wilms' tumor can be divided into 2 types, based on prognosis: favorable (over 90%) and unfavorable (6–10%) 19 . Histopathological analysis is the current gold standard for diagnosing Wilms' tumor. Surgery, chemotherapy, and radiotherapy are also used to treat Wilms' tumor 16 . The National Wilms Tumor Study Group (NWTSG)/Children's Oncology Group (COG) and the International Society of Paediatric Oncology (SIOP) have established the major guidelines regarding the management of Wilms' tumor 23 . SIOP recommends using preoperative chemotherapy to reduce the tumor size and prevent intraoperative spillage due to tumor rupture 16 . In contrast, the NWTSG/COG recommends the application of primary surgery before any adjuvant treatments 23 . The overall survival of children with Wilms' tumor in horseshoe kidney appears to be similar to that among children with Wilms' tumor in normal kidneys 11 . Conclusion Fetal Wilms’ tumor (WT) is extremely rare, but advances in fetal imaging have led to increased detection of such cases. Managing these cases remains challenging due to the complexity of treatment and the needed for preserving renal function. Prenatal ultrasound is an essential diagnostic tool for early detection and intervention. Declarations Data Availability The data used to support the findings of this case report are available from the corresponding author upon reasonable request. Informed consent Written informed consent was obtained from the mother for publication of this case report and any accompanying images. Ethical approval Not applicable. Conflict of Interest No conflicts of interest. Funding statement "No funding was used in this study." Acknowledgment The authors would like to acknowledge all the managing teams who participated in the management of this client and the accomplishment of this case report. Author Contribution Abebe Melis (A.M): Contributed to the conception and design of the work, drafted the work, and performed gross and microscopic evaluation of the specimen, and prepared the microscopic pictures.Teketel Tadesse (T.T): Contributed to the conception and design of the work, drafted the work, and performed gross and microscopic evaluation of the specimen, and prepared the gross pictures.Samson Jemal (S.J): Contributed to the conception and design of the work, drafted the work, and conducted imaging evaluation.Worku Ketema (W.K): Contributed to the conception and design of the work, drafted the work, and finalized the manuscript.All authors: Reviewed and approved the final version of the manuscript. References Lee JSSTWG. S. Malignant renal tumors in children. Luu DT, Duc NM, Tra My TT, Bang LV, Lien Bang MT, Van ND. Wilms’ Tumor in Horseshoe Kidney. Case Rep Nephrol Dial. 2021;11(2):124–8. Charlton J, Irtan S, Bergeron C, Pritchard-Jones K. Bilateral Wilms tumour: a review of clinical and molecular features. Expert Rev Mol Med. 2017;19:e8. Breslow N et al. Epidemiology of Wilms tumor. Bozlu GÇEÇ. Evaluation of renal tumors in children. Meng D, Chang X, Ren Q, Xu J, Wang H. Congenital Bilateral Wilms Tumor: A Case Report. Urology. 2021;157:242–5. Treger TD T. CTPJKBS. The genetic changes of Wilms tumour. Bechara ESCGCCD. and AJP. Fetal Wilm’s tumor detection preceding the development of isolated lateralized overgrowth of the limb. . 9, Isaacs. H J. Fetal and neonatal renal tumors. Glodny BPJHKSCHRTT et al. Kidney fusion anomalies revisited: clinical and radiological analysis of 209 cases of crossed fused ectopia and horseshoe kidney. Lee SHBMCSLJCYJK et al. Wilms’ tumor in a horseshoe kidney. Taghavi KKJMSA. The horseshoe kidney: surgical anatomy and embryology. Shah HU. O V. Multimodality imaging spectrum of complications of horseshoe kidney. Natsis KPMSAPVTIS. P. Horseshoe kidney: a review of anatomy and pathology. Surg Radiol Anat. Cascio SSBGCPGJVP. P. Vesicoureteral reflux and ureteropelvic junction obstruction in children with horseshoe kidney: treatment and outcome. Bhatnagar S. Management of Wilms’ tumor. Tkocz MKM. Tumour in horseshoe kidney – different surgical treatment shown in five example cases. Neville HRMSRHGPSYT. The occurrence of Wilms tumor in horseshoe kidneys: a report from the national wilms tumor study group (NWTSG). Dumba MJNMK. Neuroblastoma and nephroblastoma: a radiological review. Servaes SEHFSEKG. Imaging of Wilms tumor: an update. Olukayode ARIRABOGO. Pattern of computed tomography scan findings in children with Wilms’ tumor in a tertiary hospital in Lagos, Nigeria. Lonergan GJMLMAGMHSES. Nephrogenic rests, nephroblastomatosis, and associated lesions of the kidney. Radiographics. Wang JLMTDGWMJSQ. Current treatment for Wilms tumor: COG and SIOP standards. Additional Declarations No competing interests reported. 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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-5766165","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":404469736,"identity":"2737b981-dada-4255-8eb9-4ae5b0215875","order_by":0,"name":"Abebe Melis","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA6klEQVRIiWNgGAWjYDACCQY2ECXDxsB8DMRgbCBWCw8bA1saTAsBbTAtQGRGnBb+2c3HHnzMseHh4z/z7TEPg43shgPMxx/gteTOsXTDmdvSeNgkcrcb8zCkGW84wJaI32E3csykebcdBmrh3SbNw3A4ccMBHkO8WuRv5H+T/rvtPw8b/5lnQC3/gVr4P+LVYnAjh02acdsBYIgBGTwMB0C24Pe+4Z1j5oa925KBDkszk5xjkGw88zCb4Qx8WuRuNz978HObnZx8/+FnEm8q7GT7jjc/+IBPC7o7gZiZBPWjYBSMglEwCrADAKPGRz9Z/Jv+AAAAAElFTkSuQmCC","orcid":"","institution":"Hawassa University","correspondingAuthor":true,"prefix":"","firstName":"Abebe","middleName":"","lastName":"Melis","suffix":""},{"id":404469737,"identity":"300de7bf-3cdf-45f8-8402-c08841585e59","order_by":1,"name":"Teketel Tadesse","email":"","orcid":"","institution":"Hawassa University","correspondingAuthor":false,"prefix":"","firstName":"Teketel","middleName":"","lastName":"Tadesse","suffix":""},{"id":404469738,"identity":"5b42de73-3ad6-41c3-aaed-75b2c92ce96f","order_by":2,"name":"Samson Jemal","email":"","orcid":"","institution":"Naol Hospital","correspondingAuthor":false,"prefix":"","firstName":"Samson","middleName":"","lastName":"Jemal","suffix":""},{"id":404469739,"identity":"b5ecc972-fd9f-4eb1-948e-7c002b864b9d","order_by":3,"name":"Worku Ketema","email":"","orcid":"","institution":"Hawassa University","correspondingAuthor":false,"prefix":"","firstName":"Worku","middleName":"","lastName":"Ketema","suffix":""}],"badges":[],"createdAt":"2025-01-05 05:38:03","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5766165/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5766165/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":74425877,"identity":"d35e191f-fdea-4751-a286-f11dd314c4af","added_by":"auto","created_at":"2025-01-22 07:59:17","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":406743,"visible":true,"origin":"","legend":"\u003cp\u003eGross evaluation. (A, B, C), Bilateral enlarged kidneys with fused lower pole. D. Cut surface revealing multicystic spaces effacing the renal parenchyma.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-5766165/v1/1ce8ad5f461b613d9d4efebe.png"},{"id":74424265,"identity":"303cf7a3-b6a4-4a3f-bafa-6b07ff3d85f8","added_by":"auto","created_at":"2025-01-22 07:51:17","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":1048403,"visible":true,"origin":"","legend":"\u003cp\u003eMicroscopic examination (H\u0026amp;E stain). A, Medium power microscopic examination demonstrating small abortive tubules and focal blastemal element. \u0026nbsp;B, Medium power microscopic examination revealing variable sized tubules set in hypo and hypercellular stromal component.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-5766165/v1/00ab57c63f1e991e235e1463.png"},{"id":74426184,"identity":"a9ac0af9-0b02-41f7-9eef-26a7f3a057c0","added_by":"auto","created_at":"2025-01-22 08:07:22","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1923341,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5766165/v1/80064b11-00b6-4f62-b96f-c16ac57cc614.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"A rare case of Fetal bilateral Wilms’ Tumor in horseshoe Kidney: A case report","fulltext":[{"header":"Introduction","content":"\u003cp\u003eNephroblastoma, also known as Wilms' tumor (WT), is the most commonly detected pediatric malignant renal mass, accounting for 87% of all malignant renal masses and 7% of all malignant tumors found in children. \u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e,\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. The tumor is associated with undifferentiated embryonic lesions called nephrogenic rests (NRs) or, when diffuse, nephroblastomatosis. WT or NRs can occur in both kidneys, termed bilateral disease, found in only 5\u0026ndash;8% of cases\u003csup\u003e\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e. Bilateral disease can be synchronous (both kidneys affected at the same time) or metachronous (one affected after the other), which occurs in 6.3 and 0.85% WT patients respectively \u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e.The median age at which this tumor is diagnosed is three years. \u003csup\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e. Prenatal detection of Wilms tumor is extremely rare. Prenatal ultrasonography and fetal magnetic resonance imaging (MRI) has been found to be helpful in diagnosis of renal masses \u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/sup\u003e. Wilms' tumor is linked to several syndromes, such as WAGR syndrome (Wilms' tumor, aniridia, genitourinary abnormalities, and spectrum of developmental delays), Beckwith-Wiedemann syndrome, Denys-Drash syndrome, and Edwards or Perlman syndrome.\u003csup\u003e\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u003c/sup\u003e. Some cases are associated with prenatal polyhydramnios and fetal hydrops \u003csup\u003e\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e,\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u003c/sup\u003e.Horseshoe kidney occurs in around 1 in 500 instances, with a higher incidence in males\u003csup\u003e\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e. Nevertheless, the presence of Wilms' tumor in horseshoe kidney is very uncommon, with an estimated occurrence rate of roughly 0.4\u0026ndash;0.9% of all Wilms' tumors. \u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e"},{"header":"Case Presentation","content":"\u003cp\u003eOur case is a 28-year-old primigravid female patient from the Sidama region, Ethiopia, who came for the complaint of decreased abdominal girth and decreased fetal moment. Other prenatal history was unremarkable.\u003c/p\u003e\u003cp\u003eOn physical examination, her vital signs were all normal. Abdominal examination revealed 18-week sized gravid uterus.\u003c/p\u003e\u003cp\u003eOn laboratory tests: Work-up for complete blood count, liver and renal function tests were within the normal range. Her blood group and Rh were AB negative.\u003c/p\u003e\u003cp\u003eObstetric Ultrasound: Singleton intra-uterine pregnancy, alive with Biparietal diameter (BPD)measuring 22\u0026thinsp;+\u0026thinsp;3, Femoral length (FL) 22\u0026thinsp;+\u0026thinsp;6, Abdominal circumference (AC): 31 weeks. There is 8x7 cm measuring abdominopelvic mass, abdominal contents are pushed peripherally by the mass. Placenta fundal with no measurable liquor. Index: Severe oligohydramnios\u0026thinsp;+\u0026thinsp;with renal mass secondary to? Nephroblastoma top on the list.\u003c/p\u003e\u003cp\u003eHence, safe termination was decided for the indication of incompatible congenital defects based on the existing trends. We put her on maintenance fluid with Normal saline and safe medical termination was done. Sample from fetus and products of conceptus were sent for histopathologic examination.\u003c/p\u003e\u003cp\u003eSubsequent examinations of the autopsy revealed a bilaterally enlarged kidneys with fused lower pole with cut surface revealing multicystic spaces effacing the renal parenchyma (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eMicroscopic examination shows triphasic proliferation of blastemal, epithelial and stromal components which is consistent with Wilm\u0026rsquo;s tumor (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e)\u003c/p\u003e\u003cp\u003eThe mother had a smooth post-treatment course and was discharged on the 2nd day with oral antibiotics and advice for subsequent follow-ups and pregnancy\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eDuring the fetal period, the kidneys develop and ascend, developing first in the pelvis and then gradually ascending into position below the thorax, on either side of the lumbar spine. During this ascending process, the kidneys also rotate, which typically occurs by the gestational ninth week \u003csup\u003e\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u003c/sup\u003e. Renal fusion anomalies may occur during this process \u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e. The isthmus of the horseshoe kidney may contain functioning renal parenchyma or a fibrous band \u003csup\u003e\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u003c/sup\u003e. In up to 80% of cases of horseshoe kidney, the isthmus contains functional renal parenchyma tissue, and in \u0026gt;\u0026thinsp;90% of cases, fusion occurs at the lower pole \u003csup\u003e\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u003c/sup\u003e. Patients with horseshoe kidney are often asymptomatic and are typically discovered incidentally, often due to symptoms secondary to pelvic ureteric junction obstruction and infection \u003csup\u003e\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u003c/sup\u003e. These patients are thought to be at increased risk of developing malignancies, such as renal cell carcinoma, Wilms' tumor, and carcinoids, among which renal cell carcinoma is the most common \u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e. However, Wilms' tumor is the most common malignant kidney tumor identified in children \u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u003c/sup\u003e. The risk of Wilms' tumor in children with horseshoe kidney is 2\u0026ndash;6 times that of children in the general population \u003csup\u003e\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u003c/sup\u003e. Approximately 50% of Wilms' tumors in horseshoe kidney develop from the isthmus, likely due to the abnormal proliferation of metanephric blastema in the isthmus \u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e. The same anomaly that causes the development of horseshoe kidney may also lead to the development of Wilms' tumor \u003csup\u003e\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/sup\u003e. Patients with Wilms' tumors are often asymptomatic; approximately 10% are discovered incidentally after trauma, whereas 25% present with microscopic hematuria or hypertension secondary to renin production \u003csup\u003e\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u003c/sup\u003e. Ultrasound is used to diagnose horseshoe kidney, whereas Computed tomography (CT) and magnetic resonance imaging (MRI) are often used for staging purposes \u003csup\u003e\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e. On ultrasound, the mass presents as a large renal mass, which can be either solid or cystic, with large hypoechoic areas due to central necrosis and cyst formation. Areas characterized by fat deposits, calcification, or hemorrhage may appear \u003csup\u003e\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u003c/sup\u003e. On CT, the tumors are lower density and enhance less than the normal renal parenchyma. Tumors are often characterized by heterogeneous contrast enhancement and may feature punctuated calcifications \u003csup\u003e\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u003c/sup\u003e. On MRI, the tumors have low signal intensity on T1-weighted images, with either low or high signal intensity on T2-weighted images and restricted diffusivity on diffusion-weighted images. CT is also used for the detection of lung metastasis or local recurrence \u003csup\u003e\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u003c/sup\u003e. Wilms' tumors contain variable quantities of embryonic renal elements, such as blastema, epithelium, and stroma \u003csup\u003e\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e\u003c/sup\u003e. Wilms' tumor can be divided into 2 types, based on prognosis: favorable (over 90%) and unfavorable (6\u0026ndash;10%) \u003csup\u003e\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u003c/sup\u003e. Histopathological analysis is the current gold standard for diagnosing Wilms' tumor. Surgery, chemotherapy, and radiotherapy are also used to treat Wilms' tumor \u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u003c/sup\u003e. The National Wilms Tumor Study Group (NWTSG)/Children's Oncology Group (COG) and the International Society of Paediatric Oncology (SIOP) have established the major guidelines regarding the management of Wilms' tumor \u003csup\u003e\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u003c/sup\u003e. SIOP recommends using preoperative chemotherapy to reduce the tumor size and prevent intraoperative spillage due to tumor rupture \u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u003c/sup\u003e. In contrast, the NWTSG/COG recommends the application of primary surgery before any adjuvant treatments \u003csup\u003e\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u003c/sup\u003e. The overall survival of children with Wilms' tumor in horseshoe kidney appears to be similar to that among children with Wilms' tumor in normal kidneys \u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eFetal Wilms\u0026rsquo; tumor (WT) is extremely rare, but advances in fetal imaging have led to increased detection of such cases. Managing these cases remains challenging due to the complexity of treatment and the needed for preserving renal function. Prenatal ultrasound is an essential diagnostic tool for early detection and intervention.\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eData Availability\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data used to support the findings of this case report are available from the corresponding author upon reasonable request.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInformed consent\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWritten informed consent was obtained from the mother for publication of this case report and any accompanying images.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical approval\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of Interest\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo conflicts of interest.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding statement\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026quot;No funding was used in this study.\u0026quot;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgment\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors would like to acknowledge all the managing teams who participated in the management of this client and the accomplishment of this case report.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contribution\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAbebe Melis (A.M): Contributed to the conception and design of the work, drafted the work, and performed gross and microscopic evaluation of the specimen, and prepared the microscopic pictures.Teketel Tadesse (T.T): Contributed to the conception and design of the work, drafted the work, and performed gross and microscopic evaluation of the specimen, and prepared the gross pictures.Samson Jemal (S.J): Contributed to the conception and design of the work, drafted the work, and conducted imaging evaluation.Worku Ketema (W.K): Contributed to the conception and design of the work, drafted the work, and finalized the manuscript.All authors: Reviewed and approved the final version of the manuscript.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eLee JSSTWG. S. Malignant renal tumors in children.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLuu DT, Duc NM, Tra My TT, Bang LV, Lien Bang MT, Van ND. Wilms\u0026rsquo; Tumor in Horseshoe Kidney. Case Rep Nephrol Dial. 2021;11(2):124\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCharlton J, Irtan S, Bergeron C, Pritchard-Jones K. Bilateral Wilms tumour: a review of clinical and molecular features. Expert Rev Mol Med. 2017;19:e8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBreslow N et al. Epidemiology of Wilms tumor.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBozlu G\u0026Ccedil;E\u0026Ccedil;. Evaluation of renal tumors in children.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMeng D, Chang X, Ren Q, Xu J, Wang H. Congenital Bilateral Wilms Tumor: A Case Report. Urology. 2021;157:242\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTreger TD T. CTPJKBS. The genetic changes of Wilms tumour.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBechara ESCGCCD. and AJP. Fetal Wilm\u0026rsquo;s tumor detection preceding the development of isolated lateralized overgrowth of the limb.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003e. 9, Isaacs. H J. Fetal and neonatal renal tumors.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGlodny BPJHKSCHRTT et al. Kidney fusion anomalies revisited: clinical and radiological analysis of 209 cases of crossed fused ectopia and horseshoe kidney.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLee SHBMCSLJCYJK et al. Wilms\u0026rsquo; tumor in a horseshoe kidney.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTaghavi KKJMSA. The horseshoe kidney: surgical anatomy and embryology.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShah HU. O V. Multimodality imaging spectrum of complications of horseshoe kidney.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNatsis KPMSAPVTIS. P. Horseshoe kidney: a review of anatomy and pathology. Surg Radiol Anat.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCascio SSBGCPGJVP. P. Vesicoureteral reflux and ureteropelvic junction obstruction in children with horseshoe kidney: treatment and outcome.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBhatnagar S. Management of Wilms\u0026rsquo; tumor.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTkocz MKM. Tumour in horseshoe kidney\u0026thinsp;\u0026ndash;\u0026thinsp;different surgical treatment shown in five example cases.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNeville HRMSRHGPSYT. The occurrence of Wilms tumor in horseshoe kidneys: a report from the national wilms tumor study group (NWTSG).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDumba MJNMK. Neuroblastoma and nephroblastoma: a radiological review.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eServaes SEHFSEKG. Imaging of Wilms tumor: an update.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOlukayode ARIRABOGO. Pattern of computed tomography scan findings in children with Wilms\u0026rsquo; tumor in a tertiary hospital in Lagos, Nigeria.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLonergan GJMLMAGMHSES. Nephrogenic rests, nephroblastomatosis, and associated lesions of the kidney. Radiographics.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang JLMTDGWMJSQ. Current treatment for Wilms tumor: COG and SIOP standards.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"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":"Fetal Bilateral Wilms’ tumor, Horseshoe kidney, case report","lastPublishedDoi":"10.21203/rs.3.rs-5766165/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5766165/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eWilms' tumor is the most common malignant kidney tumor in children. The horseshoe kidney is the most common renal fusion malformation. However, Wilms' tumor is rarely identified in horseshoe kidney patients. The incidence of horseshoe kidney is about 1 in 400 cases. Wilms\u0026rsquo; tumor or Nephrogenic rests can occur in both kidneys, termed bilateral disease, found in only 5\u0026ndash;8% of cases. Management of bilateral Wilms\u0026rsquo; tumor presents a major clinical challenge in terms of maximizing survival, preserving renal function, and understanding underlying genetic risk. Ultrasound is used to diagnose horseshoe kidneys, whereas Computed tomography and magnetic resonance imaging are often used for staging purposes. Here, we present an extremely rare case of a fetus with a prenatal diagnosis of renal mass, and an autopsy found out to be a bilateral congenital Wilms\u0026rsquo; tumor in the horseshoe kidney. Up to our knowledge, it is the first case to be reported from Ethiopia, and there are only a few case reports worldwide.\u003c/p\u003e","manuscriptTitle":"A rare case of Fetal bilateral Wilms’ Tumor in horseshoe Kidney: A case report","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-01-22 07:51:12","doi":"10.21203/rs.3.rs-5766165/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":"57a40b38-7bfb-4e50-8b35-c1d39fd15d43","owner":[],"postedDate":"January 22nd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-01-22T07:51:12+00:00","versionOfRecord":[],"versionCreatedAt":"2025-01-22 07:51:12","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-5766165","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5766165","identity":"rs-5766165","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}