Low-grade mucinous neoplasm originating from intestinal duplication: A case report and review of the literature

Low-grade mucinous neoplasm originating from intestinal duplication: A case report and review of the literature | 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 Low-grade mucinous neoplasm originating from intestinal duplication: A case report and review of the literature Huihui Yin, Jie Yu, Yunzhao Chen This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5407266/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 24 Jan, 2025 Read the published version in World Journal of Surgical Oncology → Version 1 posted 15 You are reading this latest preprint version Abstract Background Low-grade mucinous neoplasms originate from the appendix. It is typically characterized by a low-grade mucus columnar epithelial cells lined smooth muscle, compared to normal intestinal mucosa, losing submucosa. However, unusual origin can occur, as noted in this case report. Case demonstration Herein, we reported a 33-year-old male with physical examination revealed abdominal mass. A computed tomography (CT) scan revealed a cystic mass between the pancreatic tail and the adjacent bowel duct, with an obvious enhancement of the cyst wall in enhanced scanning. Subsequently, the patient underwent surgical laparoscopic resection of masses and the resected sample was sent for pathological biopsy. According to the results, the pathology was consistent with the histological morphology and immunohistochemical characteristics of the low-grade mucinous tumors arising from intestinal duplication. 3.5 years post-resection, the patient returned to the hospital for re-examination that abdominal CT and blood tumor markers showed no signs of tumor recurrence. The case report is aimed to enhance the clinical recognition of the low-grade mucinous tumors arising from intestinal duplication and improve preoperative diagnosis rate and misdiagnosis rate. Conclusion The low-grade mucinous tumorsoriginate from the appendix mostly. This case resulted from an unusual derivation from intestinal duplication. Intestinal duplication low-grade mucinous tumors retroperitoneal pathological features Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Introduction Intestinal duplication is a rare congenital disease, and occurrence of low-grade mucinous tumors in intestinal duplications is even rarer. There had been case reports of pseudomyxoma peritonei originating from intestinal duplications [ 1 – 3 ]. However, we first reported a low-grade mucinous tumors occurring in intestinal duplications without secondary pseudomyxoma peritonei. In most patients, due to the rarity of intestinal duplications and the nonspecific early symptoms, preoperative diagnosis is not usually suspected, leading to difficulties in clinical diagnosis. This study retrospectively aimed to enhance the preoperative diagnosis rate of low-grade mucinous tumors originating from intestinal duplications for clinical and radiology physicians to avoid misdiagnosis. Case demonstration The case was a 33-year-old male patient who was admitted to the hospital due to the discovery of a pancreatic mass during a physical examination 4 days ago. Laboratory tests showed biochemical and tumor markers were normal. Abdominal CT (Figure 1) showed a low-density shadow with clear boundaries and calcifications at the edge between the tail of the pancreas and adjacent intestinal loop. The cystic part inside the lesion had a CT value of approximately 13 HU, measuring about 5.6×4.5cm. Enhancement of the lesion showed partial enhancement of the cyst wall, indicating a cystic lesion with calcification in the left upper abdominal cavity (Figure 2). The clinical diagnosis was a retroperitoneal mass, and the patient underwent laparoscopic resection of the retroperitoneal mass (Figure 3). Intraoperatively, it was found the mass existed in isolation and was not connected to the intestine and the liver, gallbladder, pancreas, spleen, small intestine, colon, and appendix showed no obvious abnormalities. The pathological examination was a cyst which sized 7.0×5.0×3.5 cm, and the smooth wall thickness was 0.1-0.6 cm, hard locally, containing yellow green viscous mucus like substance (Figure 4). Hematoxylin-eosin (HE) staining showed the cyst wall was composed of heterogenic mucinous epithelium lined with a double-layer smooth muscle, which was similar to the intestinal wall but lost normal submucosa. And a mucus lake was formed which no heteromorphic epithelium and signet ring cells were found floating (Figure 5). The local secondary dystrophic calcification and ossification occurred. Immunohistochemical staining of the mucinous tumor lesion demonstrated negative expression of cytokeratin CK-7 and Pax-8, but strongly positive expression of CK-20 (Figure 6), CDX-2 (Figure 7), MUC-2(Figure 8), Villin. The final pathological diagnosis was low-grade mucinous neoplasm originating from intestinal duplication. The patient underwent laparoscopic retroperitoneal tumor resection and was discharged 10 days after surgery without other treatment. He came to the hospital for re-examination every six months. The latest time of re-examination was August 2024. No signs of tumor recurrence were found in abdominal CT and blood tumor markers. Discussion Digestive duplication are infrequent congenital anomalies, especially in the first two years of life, rarely in adults[ 4 ]. Intestinal duplication can occur in any part of the digestive tract or adjacent organs. The ileum 30% is the first common site and followed by the ileocecal valve 30%, the jejunum 8%, the colon 6%-7% and the rectum 5%, successively[ 5 ]. Several studies have suggested that it could occur in the skin[ 6 ], the tongue[ 7 ], the liver[ 8 ]. The disease in early stage is mostly asymptomatic, or the patients presented for complications such as volvulus and intussusception and so on, which may be undetected. In neonates and infants, vomiting and distension were the most common presentations, and in older children and adolescents, pain and vomiting were the most common associations[ 5 ]. As symptoms are typically nonspecific, an initial misdiagnosis of other conditions occurs frequently. In the study, the patient was a young adult and was found an abdominal space in physical examination. At present, the mechanism of intestinal duplication is still controversial, and several hypotheses have been formulated, but the etiology of this anomaly remains largely unknown [ 9 ]. Intestinal duplications rarely undergo malignant transformation with uncommon diseases and a relatively low incidence. Only few neoplasm cases of arising from intestinal duplication have been reported, including adenocarcinoma [ 10 ], squamous carcinoma[ 11 ] and carcinoid tumors[ 12 ]. Low-grade mucinous neoplasm arising from intestinal duplication is an extremely rare origin of tumor disease. Occasionally, low-grade mucinous neoplasm occurring in the appendix. Currently, there were only 2 literature reports on low-grade mucinous tumors occurring in intestinal duplication, secondary to abdominal pseudomyxoma [ 1 , 3 ], of which involving the ovary and who underwent appendectomy 25 years earlier, and another case containing a low-grade villous adenoma[ 2 ]. Imaging examinations, including ultrasound and CT scans, can often make suspicious diagnosis. However, the final accurate diagnosis is confirmed by histopathologic verification of extensively sampled tumor. Under the guidance of abdominal ultrasound, yellow gelatinous substance can be detected through percutaneous puncture, which can strengthen the probability of PMP diagnosis [ 13 ]. Microscopically, the intestinal duplication mucosa was similar to the normal intestinal mucosa, and the inner wall was composed of four layers, including mucosa, submucosa, muscularis and adventitia. The neoplasm cyst wall was composed of a low- grade mucus columnar epithelial cells lined smooth muscle, losing submucosa. The immunophenotype expressed intestinal markers CK20 (Fig. 6 ), CDX-2 (Fig. 7 ), MUC2 (Fig. 8 ), Villin, MUC5ac and CK7 was partially expressed, indicated an origin from the gastrointestinal system. Combining with the typical jelly belly appearance and microscopic morphology and immunophenotype, ruling out any abnormalities in the appendix and mucus leakage in the peritoneal cavity, the final diagnosis was a low-grade mucinous tumor originating from intestinal duplication, and local secondary dystrophic calcification and ossification. Calcification and ossification may be caused by long-term mucus stimulation of the capsule wall fibrosis and calcification and ossification. Therefore, we reported first a low-grade mucinous tumor originating from intestinal duplication, purely, without secondary abdominal mucinous tumors. Mucous tumors, mainly occurring in the appendix were divided into low-grade mucinous tumors and high-grade mucinous tumors according to the histological structure and cellular atypia. Pseudomyxoma peritonei (PMP) is formed when the tumor penetrates the cyst wall and produces a large amount of mucus in the focus. Macroscopic tumor excision combined with heated intraperitoneal chemotherapy (HIPEC) has demonstrated inspiring results for extra-appendiceal PMP [ 14 ]. The reported patient was treated with HIPEC, which including 10 mg mitomycin and 40 mg cisplatin along with concurrent intravenous chemotherapy therapy of 5-FU (1g) with adopting a 90-min thermal cycle, and the patient had no tumor recurrence in follow-up visits 5 years after the initial operation [ 1 ]. In this case, the patient was followed up for about 3.5 years after only postoperative resection surgery and no abnormalities were observed. This indicates that accurate diagnosis is extremely important for whether there is mucus extravasation, which involves the understanding of the disease and choice of treatment methods. In conclusion, low-grade mucinous tumors stem from by far the most are the appendix. It is noteworthy that intestinal duplication could also be the origin of low-grade mucinous tumors, especially in the retroperitoneal cavity, which was also reported with secondary pseudomyxoma peritonei (PMP) [ 1 , 3 ]. Abbreviations CT: Computed tomography PMP: Pseudomyxoma peritonei HE: Hematoxylin-eosin CK: Cytokine MUC-2: Mucin 2 HIPEC: Heated intraperitoneal chemotherapy Declarations Ethics approval and consent to participate Informed consent was obtained from the patient. For retrospective studies, ethical approval was waived by Institutional Review Board of Zhejiang Provincial People’s Hospital. Acknowledgements None. Authors’ contributions Huihui Yin wrote the main manuscript text and Jie Yu prepared Figures 1, 2, 3, 4, 5, 6, 7, 8. All authors reviewed the manuscript and reviewing the case. Funding National Natural Science Foundation of China, 82273020. Availability of data and materials All the data regarding the findings are available within the manuscript. Consent for publication Consent for publication was obtained from the patient. Competing interests The authors declare that they have no competing interests. References Han XD, Zhou N, Lu YY, et al. Pseudomyxoma peritonei originating from intestinal duplication: A case report and review of the literature [J]. World J Clin Cases. 2021;9(25):7459-67. Lemahieu J, D'Hoore A, Deloose S, et al. Pseudomyxoma peritonei originating from an intestinal duplication [J]. Case Rep Pathol. 2013;2013:608016. Simons M, Ebisch I, de Hullu J, et al. A Patient With a Low-grade Mucinous Neoplasm Involving the Ovary and Pseudomyxoma Peritonei Originating in an Isolated Intestinal Duplication [J]. Int J Gynecol Pathol. 2018;37(4):338-43. Mourra N, Chafai N, Bessoud B, et al. Colorectal duplication in adults: report of seven cases and review of the literature [J]. J Clin Pathol. 2010;63(12):1080-3. Puligandla PS, Nguyen LT, St-Vil D, et al. Gastrointestinal duplications [J]. J Pediatr Surg. 2003;38(5):740-4. Mastin MR, Swanson LA, Smyrk TC, et al. Primary Cutaneous Enteric Duplication Cyst: A Novel Entity [J]. Am J Dermatopathol. 2021;43(12):e245-e7. Binet A, El Ezzi O, Meagher-Villemure K, et al. Intestinal duplication in the tongue: embryological and radiological point of view. Surg Radiol Anat. 2020;42(1):9-13. Imamoglu KH, Walt AJ. Duplication of the duodenum extending into liver [J]. Am J Surg. 1977;133(5):628-32. Grand RJ, Watkins JB, Torti FM. Development of the human gastrointestinal tract. Gastroenterology. 1976;70(5):790-810. Blank G, Königsrainer A, Sipos B, et al. Adenocarcinoma arising in a cystic duplication of the small bowel: case report and review of literature [J]. World J Surg Oncol. 2012;10:55. Hickey WF, Corson JM. Squamous cell carcinoma arising in a duplication of the colon: case report and literature review of squamous cell carcinoma of the colon and of malignancy complicating colonic duplication [J]. Cancer. 1981;47(3):602-9. Horie H, Iwasaki I, Takahashi H. Carcinoid in a gastrointestinal duplication [J]. J Pediatr Surg. 1986;21(10):902-4. Badyal RK, Khairwa A, Rajwanshi A, et al. Significance of epithelial cell clusters in pseudomyxoma peritonei [J]. Cytopathology. 2016;27(6):418-426. Rizvi SA, Syed W, Shergill R. Approach to pseudomyxoma peritonei [J]. World J Gastrointest Surg. 2018;10(5):49-56. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 24 Jan, 2025 Read the published version in World Journal of Surgical Oncology → Version 1 posted Editorial decision: Revision requested 17 Nov, 2024 Reviewers agreed at journal 15 Nov, 2024 Reviewers agreed at journal 09 Nov, 2024 Reviews received at journal 08 Nov, 2024 Reviews received at journal 08 Nov, 2024 Reviews received at journal 08 Nov, 2024 Reviewers agreed at journal 08 Nov, 2024 Reviewers agreed at journal 08 Nov, 2024 Reviews received at journal 08 Nov, 2024 Reviewers agreed at journal 08 Nov, 2024 Reviewers agreed at journal 08 Nov, 2024 Reviewers invited by journal 07 Nov, 2024 Editor assigned by journal 07 Nov, 2024 Submission checks completed at journal 07 Nov, 2024 First submitted to journal 07 Nov, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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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-5407266","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":379096877,"identity":"6f1c2c76-aa66-4d42-9d18-32e8f7e797a9","order_by":0,"name":"Huihui Yin","email":"","orcid":"","institution":"Zhejiang Provincial People's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Huihui","middleName":"","lastName":"Yin","suffix":""},{"id":379096878,"identity":"dffe9642-3b70-43f7-9e1a-42ee49f38a04","order_by":1,"name":"Jie Yu","email":"","orcid":"","institution":"Zhejiang Provincial People's 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06:38:17","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5407266/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5407266/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12957-025-03682-9","type":"published","date":"2025-01-24T15:58:25+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":71071109,"identity":"82443839-1f21-445e-a32c-0c40a7239f9c","added_by":"auto","created_at":"2024-12-10 21:50:37","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":272745,"visible":true,"origin":"","legend":"\u003cp\u003eAbdominal CT (Flat scan) showed a low-density shadow with clear boundaries and calcifications at the edge between the tail of the pancreas and adjacent intestinal loop (white arrow).\u003c/p\u003e","description":"","filename":"Figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-5407266/v1/7d03f673c7ab6eac4dc529c0.png"},{"id":71070620,"identity":"5568d503-02d5-4f50-b76a-2721edc3bc09","added_by":"auto","created_at":"2024-12-10 21:34:37","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":303524,"visible":true,"origin":"","legend":"\u003cp\u003eAbdominal CT (enhanced) showed partial enhancement of the cyst wall, indicating a cystic lesion with calcification in the left upper abdominal cavity \u0026nbsp;(white arrow).\u003c/p\u003e","description":"","filename":"Figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-5407266/v1/dd24785e73be2a19a0036fb3.png"},{"id":71070625,"identity":"4cc45b2a-6e0c-4f0f-923c-5a1ab5eb3151","added_by":"auto","created_at":"2024-12-10 21:34:38","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":199260,"visible":true,"origin":"","legend":"\u003cp\u003eIntraoperative pictures with a cystic mass.\u003c/p\u003e","description":"","filename":"Figure3.png","url":"https://assets-eu.researchsquare.com/files/rs-5407266/v1/a65b2c4392f4b739b8f74746.png"},{"id":71070622,"identity":"6256021b-9c40-43c8-aff3-f1e1069874d3","added_by":"auto","created_at":"2024-12-10 21:34:37","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":246232,"visible":true,"origin":"","legend":"\u003cp\u003eA yellow jelly-like mass existed inside.\u003c/p\u003e","description":"","filename":"Figure4.png","url":"https://assets-eu.researchsquare.com/files/rs-5407266/v1/563d87d70b1ba3705f339d96.png"},{"id":71070839,"identity":"099c459f-c751-4af7-a856-22df4e42a33f","added_by":"auto","created_at":"2024-12-10 21:42:38","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":322005,"visible":true,"origin":"","legend":"\u003cp\u003eHematoxylin-eosin (HE) (100X) showed low-grade mucinous epithelial cells lining in the capsule wall, emanating from the intestinal duplication.\u003c/p\u003e","description":"","filename":"Figure5.png","url":"https://assets-eu.researchsquare.com/files/rs-5407266/v1/272d3f51cd8e7d68a4a2fd6f.png"},{"id":71070621,"identity":"2fde12db-c46e-4004-b5dd-ebd98bf73942","added_by":"auto","created_at":"2024-12-10 21:34:37","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":293741,"visible":true,"origin":"","legend":"\u003cp\u003eImmunohistochemical stains showed positive for CK-20, (100X).\u003c/p\u003e","description":"","filename":"Figure6.png","url":"https://assets-eu.researchsquare.com/files/rs-5407266/v1/690a60578ec1945b7ca86781.png"},{"id":71070837,"identity":"deb38a6b-2bf7-4b81-83e1-1bd67588848c","added_by":"auto","created_at":"2024-12-10 21:42:37","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":227643,"visible":true,"origin":"","legend":"\u003cp\u003eImmunohistochemical stains showed positive for CDX-2 (100X).\u003c/p\u003e","description":"","filename":"Figure7.png","url":"https://assets-eu.researchsquare.com/files/rs-5407266/v1/46efafc4a2c9dda1300657d2.png"},{"id":71070626,"identity":"ab5dfada-b97c-4fdd-a76a-17abbd6fbcbc","added_by":"auto","created_at":"2024-12-10 21:34:38","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":271539,"visible":true,"origin":"","legend":"\u003cp\u003eImmunohistochemical stains showed positive for MUC-2 (100X).\u003c/p\u003e","description":"","filename":"Figure8.png","url":"https://assets-eu.researchsquare.com/files/rs-5407266/v1/46dea2ff53ddf23fbb33281d.png"},{"id":74858567,"identity":"18296199-361b-4574-9f3b-be662720a065","added_by":"auto","created_at":"2025-01-27 16:11:37","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3138133,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5407266/v1/500c5886-19f5-4674-8063-2c143fac86f8.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Low-grade mucinous neoplasm originating from intestinal duplication: A case report and review of the literature","fulltext":[{"header":"Introduction","content":"\u003cp\u003eIntestinal duplication is a rare congenital disease, and occurrence of low-grade mucinous tumors in intestinal duplications is even rarer. There had been case reports of pseudomyxoma peritonei originating from intestinal duplications [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. However, we first reported a low-grade mucinous tumors occurring in intestinal duplications without secondary pseudomyxoma peritonei. In most patients, due to the rarity of intestinal duplications and the nonspecific early symptoms, preoperative diagnosis is not usually suspected, leading to difficulties in clinical diagnosis. This study retrospectively aimed to enhance the preoperative diagnosis rate of low-grade mucinous tumors originating from intestinal duplications for clinical and radiology physicians to avoid misdiagnosis.\u003c/p\u003e"},{"header":"Case demonstration","content":"\u003cp\u003eThe case was a 33-year-old male patient who was admitted to the hospital due to the discovery of a pancreatic mass during a physical examination 4 days ago. Laboratory tests showed biochemical and tumor markers were normal. Abdominal CT (Figure 1) showed a low-density shadow with clear boundaries and calcifications at the edge between the tail of the pancreas and adjacent intestinal loop. The cystic part inside the lesion had a CT value of approximately 13 HU, measuring about 5.6×4.5cm. Enhancement of the lesion showed partial enhancement of the cyst wall, indicating a cystic lesion with calcification in the left upper abdominal cavity (Figure 2). The clinical diagnosis was a retroperitoneal mass, and the patient underwent laparoscopic resection of the retroperitoneal mass (Figure 3). Intraoperatively, it was found the mass existed in isolation and was not connected to the intestine and the liver, gallbladder, pancreas, spleen, small intestine, colon, and appendix showed no obvious abnormalities. The pathological examination was a cyst which sized 7.0×5.0×3.5 cm, and the smooth wall thickness was 0.1-0.6 cm, hard locally, containing yellow green viscous mucus like substance (Figure 4).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eHematoxylin-eosin (HE) staining showed the cyst wall was composed of heterogenic mucinous epithelium lined with a double-layer smooth muscle, which was similar to the intestinal wall but lost normal submucosa. And a mucus lake was formed which no heteromorphic epithelium and signet ring cells were found floating (Figure 5). The local secondary dystrophic calcification and ossification occurred. Immunohistochemical staining of the mucinous tumor lesion demonstrated negative expression of cytokeratin CK-7 and Pax-8, but strongly positive expression of CK-20 (Figure 6), CDX-2 (Figure 7), MUC-2(Figure 8), Villin. The final pathological diagnosis was low-grade\u0026nbsp;mucinous\u0026nbsp;neoplasm originating from intestinal duplication.\u003c/p\u003e\n\u003cp\u003eThe patient underwent laparoscopic retroperitoneal tumor resection and was discharged 10 days after surgery without other treatment. He came to the hospital for re-examination every six months. The latest time of re-examination was August 2024. No signs of tumor recurrence were found in abdominal CT and blood tumor markers.\u0026nbsp;\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eDigestive duplication are infrequent congenital anomalies, especially in the first two years of life, rarely in adults[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Intestinal duplication can occur in any part of the digestive tract or adjacent organs. The ileum 30% is the first common site and followed by the ileocecal valve 30%, the jejunum 8%, the colon 6%-7% and the rectum 5%, successively[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Several studies have suggested that it could occur in the skin[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e], the tongue[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], the liver[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. The disease in early stage is mostly asymptomatic, or the patients presented for complications such as volvulus and intussusception and so on, which may be undetected. In neonates and infants, vomiting and distension were the most common presentations, and in older children and adolescents, pain and vomiting were the most common associations[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. As symptoms are typically nonspecific, an initial misdiagnosis of other conditions occurs frequently. In the study, the patient was a young adult and was found an abdominal space in physical examination. At present, the mechanism of intestinal duplication is still controversial, and several hypotheses have been formulated, but the etiology of this anomaly remains largely unknown [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIntestinal duplications rarely undergo malignant transformation with uncommon diseases and a relatively low incidence. Only few neoplasm cases of arising from intestinal duplication have been reported, including adenocarcinoma [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e], squamous carcinoma[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e] and carcinoid tumors[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Low-grade mucinous neoplasm arising from intestinal duplication is an extremely rare origin of tumor disease. Occasionally, low-grade mucinous neoplasm occurring in the appendix. Currently, there were only 2 literature reports on low-grade mucinous tumors occurring in intestinal duplication, secondary to abdominal pseudomyxoma [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e], of which involving the ovary and who underwent appendectomy 25 years earlier, and another case containing a low-grade villous adenoma[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Imaging examinations, including ultrasound and CT scans, can often make suspicious diagnosis. However, the final accurate diagnosis is confirmed by histopathologic verification of extensively sampled tumor. Under the guidance of abdominal ultrasound, yellow gelatinous substance can be detected through percutaneous puncture, which can strengthen the probability of PMP diagnosis [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eMicroscopically, the intestinal duplication mucosa was similar to the normal intestinal mucosa, and the inner wall was composed of four layers, including mucosa, submucosa, muscularis and adventitia. The neoplasm cyst wall was composed of a low- grade mucus columnar epithelial cells lined smooth muscle, losing submucosa. The immunophenotype expressed intestinal markers CK20 (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e), CDX-2 (Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e), MUC2 (Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e8\u003c/span\u003e), Villin, MUC5ac and CK7 was partially expressed, indicated an origin from the gastrointestinal system. Combining with the typical jelly belly appearance and microscopic morphology and immunophenotype, ruling out any abnormalities in the appendix and mucus leakage in the peritoneal cavity, the final diagnosis was a low-grade mucinous tumor originating from intestinal duplication, and local secondary dystrophic calcification and ossification. Calcification and ossification may be caused by long-term mucus stimulation of the capsule wall fibrosis and calcification and ossification. Therefore, we reported first a low-grade mucinous tumor originating from intestinal duplication, purely, without secondary abdominal mucinous tumors.\u003c/p\u003e \u003cp\u003eMucous tumors, mainly occurring in the appendix were divided into low-grade mucinous tumors and high-grade mucinous tumors according to the histological structure and cellular atypia. Pseudomyxoma peritonei (PMP) is formed when the tumor penetrates the cyst wall and produces a large amount of mucus in the focus. Macroscopic tumor excision combined with heated intraperitoneal chemotherapy (HIPEC) has demonstrated inspiring results for extra-appendiceal PMP [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. The reported patient was treated with HIPEC, which including 10 mg mitomycin and 40 mg cisplatin along with concurrent intravenous chemotherapy therapy of 5-FU (1g) with adopting a 90-min thermal cycle, and the patient had no tumor recurrence in follow-up visits 5 years after the initial operation [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. In this case, the patient was followed up for about 3.5 years after only postoperative resection surgery and no abnormalities were observed. This indicates that accurate diagnosis is extremely important for whether there is mucus extravasation, which involves the understanding of the disease and choice of treatment methods.\u003c/p\u003e \u003cp\u003eIn conclusion, low-grade mucinous tumors stem from by far the most are the appendix. It is noteworthy that intestinal duplication could also be the origin of low-grade mucinous tumors, especially in the retroperitoneal cavity, which was also reported with secondary pseudomyxoma peritonei (PMP) [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e].\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eCT: Computed tomography\u003c/p\u003e\n\u003cp\u003ePMP: Pseudomyxoma peritonei\u003c/p\u003e\n\u003cp\u003eHE: Hematoxylin-eosin\u003c/p\u003e\n\u003cp\u003eCK: Cytokine\u003c/p\u003e\n\u003cp\u003eMUC-2: Mucin 2\u003c/p\u003e\n\u003cp\u003eHIPEC: Heated intraperitoneal chemotherapy\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003eEthics approval and consent to participate Informed consent was obtained from the patient. For retrospective studies, ethical approval was waived by Institutional Review Board of Zhejiang Provincial People\u0026rsquo;s Hospital.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eHuihui Yin wrote the main manuscript text and Jie Yu prepared Figures 1, 2, 3, 4, 5, 6, 7, 8. All authors reviewed the manuscript and reviewing the case.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNational Natural Science Foundation of China, 82273020.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll the data regarding the findings are available within the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eConsent for publication was obtained from the patient.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eHan XD, Zhou N, Lu YY, et al. Pseudomyxoma peritonei originating from intestinal duplication: A case report and review of the literature [J]. World J Clin Cases. 2021;9(25):7459-67.\u003c/li\u003e\n\u003cli\u003eLemahieu J, D\u0026apos;Hoore A, Deloose S, et al. Pseudomyxoma peritonei originating from an intestinal duplication [J]. Case Rep Pathol. 2013;2013:608016. \u003c/li\u003e\n\u003cli\u003eSimons M, Ebisch I, de Hullu J, et al. A Patient With a Low-grade Mucinous Neoplasm Involving the Ovary and Pseudomyxoma Peritonei Originating in an Isolated Intestinal Duplication [J]. Int J Gynecol Pathol. 2018;37(4):338-43.\u003c/li\u003e\n\u003cli\u003eMourra N, Chafai N, Bessoud B, et al. Colorectal duplication in adults: report of seven cases and review of the literature [J]. J Clin Pathol. 2010;63(12):1080-3.\u003c/li\u003e\n\u003cli\u003ePuligandla PS, Nguyen LT, St-Vil D, et al. Gastrointestinal duplications [J]. J Pediatr Surg. 2003;38(5):740-4.\u003c/li\u003e\n\u003cli\u003eMastin MR, Swanson LA, Smyrk TC, et al. Primary Cutaneous Enteric Duplication Cyst: A Novel Entity [J]. Am J Dermatopathol. 2021;43(12):e245-e7.\u003c/li\u003e\n\u003cli\u003eBinet A, El Ezzi O, Meagher-Villemure K, et al. Intestinal duplication in the tongue: embryological and radiological point of view. Surg Radiol Anat. 2020;42(1):9-13.\u003c/li\u003e\n\u003cli\u003eImamoglu KH, Walt AJ. Duplication of the duodenum extending into liver [J]. Am J Surg. 1977;133(5):628-32.\u003c/li\u003e\n\u003cli\u003eGrand RJ, Watkins JB, Torti FM. Development of the human gastrointestinal tract. Gastroenterology. 1976;70(5):790-810.\u003c/li\u003e\n\u003cli\u003eBlank G, K\u0026ouml;nigsrainer A, Sipos B, et al. Adenocarcinoma arising in a cystic duplication of the small bowel: case report and review of literature [J]. World J Surg Oncol. 2012;10:55.\u003c/li\u003e\n\u003cli\u003eHickey WF, Corson JM. Squamous cell carcinoma arising in a duplication of the colon: case report and literature review of squamous cell carcinoma of the colon and of malignancy complicating colonic duplication [J]. Cancer. 1981;47(3):602-9.\u003c/li\u003e\n\u003cli\u003eHorie H, Iwasaki I, Takahashi H. Carcinoid in a gastrointestinal duplication [J]. J Pediatr Surg. 1986;21(10):902-4.\u003c/li\u003e\n\u003cli\u003eBadyal RK, Khairwa A, Rajwanshi A, et al. Significance of epithelial cell clusters in pseudomyxoma peritonei [J]. Cytopathology. 2016;27(6):418-426.\u003c/li\u003e\n\u003cli\u003eRizvi SA, Syed W, Shergill R. Approach to pseudomyxoma peritonei [J]. World J Gastrointest Surg. 2018;10(5):49-56.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"world-journal-of-surgical-oncology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"wjso","sideBox":"Learn more about [World Journal of Surgical Oncology](http://wjso.biomedcentral.com)","snPcode":"12957","submissionUrl":"https://submission.nature.com/new-submission/12957/3","title":"World Journal of Surgical Oncology","twitterHandle":"@OncoBioMed","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Intestinal duplication, low-grade mucinous tumors, retroperitoneal, pathological features","lastPublishedDoi":"10.21203/rs.3.rs-5407266/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5407266/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eLow-grade mucinous neoplasms originate from the appendix. It is typically characterized by a low-grade mucus columnar epithelial cells lined smooth muscle, compared to normal intestinal mucosa, losing submucosa. However, unusual origin can occur, as noted in this case report.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCase demonstration\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eHerein, we reported a 33-year-old male with physical examination revealed abdominal mass. A computed tomography (CT) scan revealed a cystic mass between the pancreatic tail and the adjacent bowel duct, with an obvious enhancement of the cyst wall in enhanced scanning. Subsequently, the patient underwent surgical laparoscopic resection of masses and the resected sample was sent for pathological biopsy. According to the results, the pathology was consistent with the histological morphology and immunohistochemical characteristics of the low-grade mucinous tumors arising from intestinal duplication. 3.5 years post-resection, the patient returned to the hospital for re-examination that abdominal CT and blood tumor markers showed no signs of tumor recurrence. The case report is aimed to enhance the clinical recognition of the low-grade mucinous tumors arising from intestinal duplication and improve preoperative diagnosis rate and misdiagnosis rate.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe low-grade mucinous tumorsoriginate from the appendix mostly. This case resulted from an unusual derivation from intestinal duplication.\u003c/p\u003e","manuscriptTitle":"Low-grade mucinous neoplasm originating from intestinal duplication: A case report and review of the literature","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-12-10 21:34:32","doi":"10.21203/rs.3.rs-5407266/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-11-17T16:34:53+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"43201483037638235233125568984709046167","date":"2024-11-15T09:46:35+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"298449206714169691033921953025707254999","date":"2024-11-09T18:36:57+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-11-08T21:03:38+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-11-08T13:13:00+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-11-08T13:03:16+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"176470654908867548141145494474410233258","date":"2024-11-08T12:10:47+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"175410263041617355160446503110923598810","date":"2024-11-08T07:42:32+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-11-08T07:14:14+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"102996429657900141554927776595246832857","date":"2024-11-08T06:53:01+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"189533987921899568283501173743213772282","date":"2024-11-08T05:57:25+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-11-08T04:03:18+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-11-08T02:21:41+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-11-07T22:44:00+00:00","index":"","fulltext":""},{"type":"submitted","content":"World Journal of Surgical Oncology","date":"2024-11-07T06:34:13+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"world-journal-of-surgical-oncology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"wjso","sideBox":"Learn more about [World Journal of Surgical Oncology](http://wjso.biomedcentral.com)","snPcode":"12957","submissionUrl":"https://submission.nature.com/new-submission/12957/3","title":"World Journal of Surgical Oncology","twitterHandle":"@OncoBioMed","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"cee269c2-197f-4320-ab80-93eb4035bbba","owner":[],"postedDate":"December 10th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-01-27T16:05:17+00:00","versionOfRecord":{"articleIdentity":"rs-5407266","link":"https://doi.org/10.1186/s12957-025-03682-9","journal":{"identity":"world-journal-of-surgical-oncology","isVorOnly":false,"title":"World Journal of Surgical Oncology"},"publishedOn":"2025-01-24 15:58:25","publishedOnDateReadable":"January 24th, 2025"},"versionCreatedAt":"2024-12-10 21:34:32","video":"","vorDoi":"10.1186/s12957-025-03682-9","vorDoiUrl":"https://doi.org/10.1186/s12957-025-03682-9","workflowStages":[]},"version":"v1","identity":"rs-5407266","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5407266","identity":"rs-5407266","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}