Clinical, Endoscopic, Pathological Characteristics and Managements of Cap Polyposis: A Real-world Study from China

Clinical, Endoscopic, Pathological Characteristics and Managements of Cap Polyposis: A Real-world Study from China | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Clinical, Endoscopic, Pathological Characteristics and Managements of Cap Polyposis: A Real-world Study from China Lingyu Huang, Xiaoying Lou, Chunyu Chen, Yi Lu This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3921061/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 and aims: Cap polyposis (CP) is a rare kind of benign disease, and the majority of previously published articles on it involve a small number of patients. Hence, we summarized our experience to add more data, hoping to raise awareness of this disease. Methods From January, 1st, 2017 to November, 1st, 2021, consecutive patients diagnosed with CP were retrospectively reviewed. Their medical histories, and laboratory, imaging, endoscopic, and pathology results were analyzed. We made telephone calls to the patients and searched for the information in our electronic medical records to obtain the follow-up results. Results Forty-one patients were chosen for analysis. The median age of the patients was 20 years old, and 90.24% (37 patients) of the patients were male. There were multiple and combined treatments for these patients. These treatments can be mainly divided into 3 categories: medical therapy, endotherapy and surgery. Medical therapy could help to diminish the size of the polyps but was difficult to resolve; however, the patients’ symptoms could be diminished. Twenty-three patients received surgical resection, and 12 patients received endotherapy. We further compared the two methods of polyp resection. Both endotherapy and surgery were safe, and the recurrence risk was not significantly different between the two kinds of therapy (P = 0.321). Conclusions The clinical improvement of medical treatments was not satisfactory, and endotherapy or surgical resection could remove the polyposis and provide temporary relief, but the recurrence rates were high. Cap polyposis Helicobacter pylori treatment colonoscopy resection Figures Figure 1 Figure 2 Figure 3 INTRODUCTION Cap polyposis (CP) is a rare kind of benign disease, that is usually located in the rectum and sometimes in the colon or stomach [ 1 – 5 ] . It was first described by Williams et al. in 1985, and as the name implies, polyps have a “cap” formed by granulation tissue covered with fibrinopurulent exudates [ 4 ] . The etiology of CP is still unclear and might be associated with mucosal prolapse, inflammation, infection with Helicobacter pylori ( H. pylori ) or other microorganisms, and dysbacteriosis [ 2 , 6 – 9 ] . The clinical manifestations of CP are constipation, diarrhea, abdominal pain, mucous stool, hematochezia, and hypoproteinemia [ 2 , 10 , 11 ] . Endoscopically, we can usually find multiple erythematous, sessile polyps covered by fibrinopurulent exudates of different sizes, and they are often located at the apices of the transverse mucosal folds with normal mucosa between the polyps. These characteristics help us to differentiate CP from inflammatory bowel disease (IBD) and cancer in endoscopy [ 12 ] . In imaging examinations, CP is sometimes misdiagnosed as cancer, and surgery might be subsequently suggested to the patient. Hence, improving the diagnostic accuracy before surgery is very important. There are a variety of therapies for CP, such as H. pylori eradication, antibiotics, steroids, 5-amino salicylic acids (5-ASAs), infliximab, and endoscopic or surgical resection [ 2 , 6 , 13 ] . However, for now, no standard therapy has been recommended for CP, as sometimes the polyps are not resolved or reoccur [ 2 ] . The majority of the previously published articles on this issue are case reports or case series with a small number of patients; hence, we summarized the experience in our hospital to add more data, hoping to raise the physicians’ and surgeons’ awareness of this disease. METHODS Patients From January, 1st, 2017 to November, 1st, 2021, consecutive patients diagnosed with CP in our hospital were retrospectively reviewed. The patients were identified from the pathology database in our hospital. The inclusion criteria were as follows: a. patients with confirmed CP, meaning the endoscopy showed multiple polyps covered by fibrinopurulent exudates, and pathology showed inflammatory polyps covered by a thick layer of fibrinopurulent exudate, forming the “cap” structure; and b. patients whose clinical information could be obtained. The exclusion criteria were as follows: a. foreigners; b. patients without endoscopic pictures; c. patients that did not receive any treatment in our hospital; d. patients with IBD; and e. patients with parastomal polyps. Information collected The following information was collected in our electronic medical records: age, gender, symptoms, medical histories, laboratory tests [mainly hemoglobin, platelet, white blood cell, neutrophils, serum albumin (ALB), high sensitivity C reactive protein (hs-CRP)], imaging results [contrast-enhanced abdominal computed tomography (CT) or magnetic resonance imaging (MRI)], endoscopic findings (mainly gastroduodenoscopy and ileocolonoscopy), rectum ultrasound, pathology results, final diagnosis, and treatments of the patients. We made telephone calls to the patients and searched for the information in our electronic medical records to obtain the follow-up results of the patients. Statistical Analysis IBM SPSS Statistics Version 22 was used to perform the statistical analyses. Continuous variables with normal distribution are presented as mean (standard deviation, SD), and those without normal distribution are presented as median (interquartile range, IQR). Categorical variables were expressed as numbers (percentages), and they were tested by using the χ 2 test. To compare the recurrence rates and time of endotherapy and surgical resection, we used the Kaplan‒Meier method to analyze the recurrence results. The endpoint was defined as the first recurrence since endotherapy/surgical resection, and recurrence was defined as polyps recurred in endoscopy or in digital rectal examination, or symptoms appeared again (as not all patients had endoscopy reexamination). RESULTS Basic information, laboratory, imaging and endoscopic characteristics We chose 41 patients with CP for final analysis, among whom, 7 patients had received endotherapy or surgery in other hospitals before. The basic information, laboratory results, and imaging characteristics of the patients are presented in Table 1 . Table 1 Basic information, laboratory and imaging characteristics Results Sex, M (n, %) 37 (90.24%) Age, years (median, IQR) 20 (14) Symptoms (n, %) * Hematochezia 29 (70.73%) Increased stool frequency 5 (12.20%) Difficult defecation or constipation 5 (12.20%) Prolapse of mass 15 (36.59%) Tenesmus 7 (17.07%) Abdominal pain 4 (9.76%) Diarrhea 3 (7.32%) No symptom 4 (9.76%) Disease course, months (median, IQR) 12 (33) Laboratory Results (n, %) Anemia 8 (19.51%) Thrombocytosis 16 (39.02%) Leukocytosis 1 (2.44%) Elevated hs-CRP 3 (3/36, 8.33%) Positive 13 C urea breath test 8 (8/13, 61.54%) Positive serum antibody of H. pylori 0 (0/8, 0) Imaging Results (n, %) Contrast-enhanced abdominal CT Benign lesions 10 (10/19, 52.63%) Malignant lesions 5 (5/19, 26.32%) Unclear 3 (3/19, 15.79%) Normal 1 (1/19, 5.26%) Contrast-enhanced abdominal MRI Benign lesions 19 (19/22, 86.36%) Malignant lesions 3 (3/19, 13.64%) IQR: interquartile range; hs-CRP, high sensitivity C reactive protein; CT, computed tomography; MRI, magnetic resonance imaging Anemia: hemoglobin < 120g/L for male and 3*10^9/L; leukocytosis: white blood cell > 10*10^9/L; elevated hs-CRP: hs-CRP > 3mg/L. * some patients had more than one symptom In endoscopic findings, multiple erythematous, polyps covered by rich exudates of different sizes were frequently found (Fig. 1 ). For 22 patients, the involved site was the rectum alone, and for another 19 patients, both the anus and rectum were involved. In 11 patients, the number of polyps was less than 5, while for others, the number of polyps was ≥ 5. Pathological findings showed polyps covered with fibrous purulent exudates and inflammatory granulation tissue forming a “cap” structure, with crypt dilatation and mucous oversecretion within the crypts; ischemic changes with crypt atrophy and interstitial fibrous tissue hyperplasia mimicking rectal prolapse could also be observed (Fig. 2 ). Treatments and follow-up results As no standard therapy has been recommended for CP, there were multiple and combined treatments for these patients. These treatments can be mainly divided into 3 categories: medical therapy (including observation, H. pylori eradication, corticoids enema, oral metronidazole, mesalazine anal plug/enema/oral, and biofeedback therapy), endotherapy [including polypectomy with snare, and endoscopic mucosal resection (EMR)], and surgery (including transanal polypectomy, laparoscopic rectum resection, and laparoscopic rectal fixation). The explicit details are presented in the supplementary Table S1 . From the follow-up results, we found that medical therapy could help to diminish the size of the polyps but was difficult to resolve (Fig. 1 C); however, the patients’ symptoms could be resolved. Twenty-three patients received surgical resection and 12 patients received endotherapy. We further compared their efficacy and safety. Both could resolve the polyps, but with high recurrence. Endotherapy and surgery were both safe, and the mortality was 0. Only 1 patient (8.33%) who received endoscopic polypectomy with snare was complicated with slight bleeding, and emergent colonoscopy found no signs of active bleeding; 1 patient (4.35%) who received transanal + laparoscopic partial rectum resection had anastomotic leakage, and was treated by conservative methods; another 1 patient (4.35%) who received laparoscopic partial rectum resection + ileostomy had anastomotic stricture, and was treated by endoscopic stricture dilation and incision. The patients who received polyp resection were followed for a median of 26 (IQR 19) months (1 patient who received surgical resection was lost). Eighteen patients (51.43%) had recurrence, and the recurrence rate was not significantly different between endotherapy and surgical resection (41.67% vs. 59.09% P = 0.331). Kaplan‒Meier curves (Fig. 3 ) further supported that, the recurrence risk was not significantly different between the two kinds of therapy (P = 0.321). Literature review We also summarized the literature on this issue [ 2 , 6 , 7 , 9 , 14 – 19 ] , and evaluated the percentage of clinical improvement of these treatments (Table 2 ). Table 2 Efficacy Ratio by Treatment in the Previously Published Cases Treatments Effective cases/ total cases Efficacy ratio(%) Observation 6/7 85.7 Avoiding straining at defecation 2/5 40 Total parental nutrition 0/5 0 Metronidazole * 7/22 31.8 Quinolone 0/2 0 Steroids (oral) 2/17 11.8 Steroids (enema or suppo) 4/15 26.7 Aminosalicylates (oral) 0/24 0 Aminosalicylates (enema or suppo) 1/4 25 Helicobacter pylori eradication # 15/16 93.8 Infliximab 2/5 40 Resection (endoscopic or surgical) 23/37 62.2 *1effective case used metronidazole + amoxicillin; #1 effective case combined steroids oral and enema, and 1 case failed was H. pylori negative. DISCUSSION CP is a relatively rare disease that is still not well recognized by physicians and surgeons, and currently, fewer than 100 cases have been published in the literature [ 12 ] . In our study, most of the patients were very young, their median age was only 20 years old, and some of them were annoyed by this disease affecting their normal work and study status. Hence, we thought we should pay more attention to this disease. Here we shared the experience in our hospital to add more data. The majority of the patients were male, which was in accordance with previous literature [ 6 , 20 , 21 ] . In 2012, Papaconstantinou et al. summarized the cases of CP [ 20 ] , and most of the patients were older than 50 years of age, but later, Brunner et al. summarized that children or younger populations also would develop CP [ 2 ] . The laboratory, and imaging characteristics of CP were not that specific. A portion of them would have anemia and thrombocytosis, while leukocytosis or elevated hs-CRP was not that common. Additionally, we should be aware that a certain number of patients would be misdiagnosed with malignant lesions in contrast-enhanced CT or MRI, in which the rates were 26.32% and 13.64%, respectively. Rectal cancer usually presents as a mass and seldomly multiple polyps (unless familial adenomatous polyposis), and repeated biopsy does not support malignant changes. If differentiation is still difficult, then a large piece of the polyp should be resected to help make a diagnosis. IBD is also an important differential diagnosis, especially in children: it was the initial diagnosis in 75% of the reports on children [ 22 ] . However, endoscopically, ulcerative colitis has background mucous change, while CP is usually characterized by multiple polyps covered by fibrinopurulent exudates with normal mucosa between the polyps, and they have different pathologic features. The relationship between CP and mucosal prolapse syndrome (MPS) is still debated. Some patients with CP have symptoms of prolapse. Cambell et al. supposed that abnormal colonic motility may lead to prolapse of the mucosa at the apices of transverse mucosal folds and cause ischemic changes [ 10 ] . The pathology includes fibromuscular obliteration of the lamina propria, granulation tissue, and elongated, hyperplastic glands. These features can also appear in MPS. However, they have some differences. First, fibromuscular obliteration is more marked in cap polyposis; second, CP can be found in both the colon and rectum, while MPS is usually confined to the rectum; third, the two diseases have different endoscopic ultrasound sonography images, as CP shows significant thickening of the mucosa, whereas MPS has remarkable thickening of the submucous [ 21 , 23 , 24 ] . To date, there is no standard or optimal therapy for CP, as its cause remains unclear. On the strength of previously published literature, various kinds of treatments have been tried, including medical therapies (observation, steroids, aminosalicylates, infliximab, metronidazole, H. pylori eradication, and so on), and endoscopic and surgical resection. But the clinical outcomes were heterogeneous. Some patients had spontaneous remission, while some needed surgical resection and still experienced recurrence [ 6 ] . Some investigators believed that, in adults, polypectomy should be performed to alleviate symptoms. However, in children, medical treatments were preferred. If the disease persists or recurs with medical treatment, then we should consider resection [ 2 , 25 ] . In our study, we further compared the long-term effectiveness of endotherapy and surgical resection, although with a small number of patients, we found that, the recurrence risk had no significant difference. However, we combined several different means of endotherapy or surgical resection in the analysis, and we think that if we could accumulate more patients, then maybe we can find a certain means of resection with the best short-term and long-term outcomes. Based on the literature review [ 2 , 6 , 7 , 9 , 14 – 19 , 26 ] and our own data, we thought that, if the patient was H. pylori positive, then H. pylori eradication combined with other therapies might be useful. There were 7 patients who were tested to have H. pylori , 5 of them had improvement after H. pylori eradication, the other two was lost. H. pylori negative, although various means tried, the outcome was not that good. Moreover, for those with rectal prolapse, if the situation of rectal prolapse was not treated, then CP seemed to recur repeatedly. The goal of CP treatment is another question that we need to consider. During follow-up, some patients might have no symptoms, but the colonoscopy still showed polyps with smaller sizes (or recurrence of polyps). They felt very well, and did not want to see the doctors for further treatment at the moment. Should the patients receive treatments until the disappearance of all the polyps, until the disappearance of all the symptoms or until the symptoms do not influence the patient’s work and life? The above questions remain to be answered. The natural course of CP is largely unknown, and if asymptomatic or slightly symptomatic CP is left untreated, the chance and risk of developing malignant lesions are also unknown. In this study, no malignant lesions were observed during follow-up. In the future, if we can obtain more information on the abovementioned aspects, we will decide the goal of CP treatment and the follow-up strategy There are some limitations in this study. First, due to the rarity of CP, it was very difficult to conduct a prospective, large sample-sized study, so we only retrospectively reviewed the clinical data of these patients, and because of the real world setting and the retrospective nature of the study, the treatment options were not chosen following a preestablished algorithm, and the pre-treatment conditions was hard to evaluate in different groups. Second, as no standard therapy for CP is recommended, the treatments varied greatly in different patients, and even in the same patients but in different periods; moreover, sometimes combined treatments were used. It was very difficult to simply generalize these therapies into several kinds and evaluate their efficacy. Third, as not all patients received colonoscopy during follow-up, in this study, recurrence was defined as polyps recurred in endoscopy or digital rectal examination, or symptoms appeared again. However, in some patients, they might have no symptoms, but colonoscopy would show polyp recurrence. If we defined recurrence as polyps recurred in endoscopy, then the recurrence rates in this study were underestimated. [ 26 ] In conclusion, CP is a disease with an increasing incidence rate that is affecting mostly young males and it easily recurs. Endoscopic and imaging features can mimic IBD or rectal cancer, and their relationship with MPS is still under debate. The clinical improvement of medical treatments was not satisfactory and was inconsistent. Endotherapy or surgical resection could remove the polyposis and provide temporary relief, but the recurrence rates were high, with no difference between the two methods. Declarations Ethics approval The study protocol was approved by the Institutional Review Board (IRB) of The Sixth Affiliated Hospital, Sun Yat-sen University, and the requirement for signed informed consent was waived by the IRB. The approval number was 2021ZSLYEC-455 and the approval date was November 22, 2021. All methods were performed in accordance with the relevant guidelines and regulations. Funding Declaration This study was supported by The Sixth Affiliated Hospital of Sun Yat-Sen University Clinical Research- “1010” Program, the program of Guangdong Provincial Clinical Research Center for Digestive Diseases (2020B1111170004), and National Key Clinical Discipline. Competing Interest declaration None. Authors contribution Lingyu Huang collected the data, performed the statistical analysis and wrote the manuscript draft. Xiaoying Lou collected the data, pathological images, and performed the statistical analysis. Chunyu Chen collected the data. Yi Lu designed the study, wrote and revised the manuscript. Availability of data and materials The datasets used are available from the corresponding author on reasonable request. References Oiya H, Okawa K, Aoki T, et al. Cap polyposis cured by Helicobacter pylori eradication therapy[J]. J Gastroenterol, 2002,37(6):463-466. Brunner M, Agaimy A, Atreya R, et al. Cap polyposis in children: case report and literature review[J]. International journal of colorectal disease, 2019,34(2):363-368. Esaki M, Matsumoto T, Kobayashi H, et al. Cap polyposis of the colon and rectum: an analysis of endoscopic findings[J]. Endoscopy, 2001,33(3):262-266. GT W, HJR B, BC M. Inflammatory cap polyps of the large intestine [abstract][J]. Br J Surg, 1985,72(Suppl):133. Da C A R, Castanheira A, Silva A. Unusual colon polyps. Diagnosis: Cap polyposis[J]. Gastroenterology, 2011,141(4):e1-e2. Suzuki H, Sato M, Akutsu D, et al. A case of cap polyposis remission by betamethasone enema after antibiotics therapy including Helicobacter pylori eradication[J]. Journal of gastrointestinal and liver diseases : JGLD, 2014,23(2):203-206. Murata M, Sugimoto M, Ban H, et al. Cap polyposis refractory to Helicobacter pylori eradication treated with endoscopic submucosal dissection[J]. World J Gastrointest Endosc, 2017,9(10):529-534. Konishi T, Watanabe T, Takei Y, et al. Cap polyposis: an inflammatory disorder or a spectrum of mucosal prolapse syndrome?[J]. Gut, 2005,54(9):1342-1343. Okamoto K, Watanabe T, Komeda Y, et al. Dysbiosis-Associated Polyposis of the Colon-Cap Polyposis[J]. Frontiers in immunology, 2018,9:918. Campbell A P, Cobb C A, Chapman R W, et al. Cap polyposis--an unusual cause of diarrhoea[J]. Gut, 1993,34(4):562-564. Oshitani N, Moriyama Y, Matsumoto T, et al. Protein-losing enteropathy from cap polyposis[J]. Lancet, 1995,346(8989):1567. Aggarwal A, Lang A, Krigman H R, et al. Vascular Malformation and CAP Polyposis: A New Insight into Pathophysiology or Fortuitous Association?[J]. Fetal Pediatr Pathol, 2021:1-6. Maunoury V, Breisse M, Desreumaux P, et al. Infliximab failure in cap polyposis[J]. Gut, 2005,54(2):313-314. Monsalve A S, Miranda G P, Santander V C. Endoscopic mucosal resection for cap poliposis treatment[J]. Rev Esp Enferm Dig, 2020,112(2):155. Tamura K, Matsuda K, Yokoyama S, et al. Successful laparoscopic resection for cap polyposis: case report, literature review[J]. Surgical case reports, 2018,4(1):69. Anuchapreeda S, Phengsuthi P, Aumpansub P, et al. Polypectomy for Recurrent Inflammatory Cap Polyposis Combined with Argon Plasma Coagulation[J]. ACG Case Rep J, 2018,5:e35. Kim S C, Kang M J, Jeong Y J, et al. A Case of Cap Polyposis with Epidermal Nevus in an Infant[J]. J Korean Med Sci, 2017,32(5):880-884. Batra S, Johal J, Lee P, et al. Cap Polyposis Masquerading as Inflammatory Bowel Disease in a Child[J]. J Pediatr Gastroenterol Nutr, 2018,67(3):e57. Arana R, Fléjou J F, Parc Y, et al. Cap polyposis and colitis cystica profunda: a rare association[J]. Histopathology, 2014,64(4):604-607. Papaconstantinou I, Karakatsanis A, Benia X, et al. Solitary rectal cap polyp: Case report and review of the literature[J]. World J Gastrointest Surg, 2012,4(6):157-162. Li J H, Leong M Y, Phua K B, et al. Cap polyposis: a rare cause of rectal bleeding in children[J]. World J Gastroenterol, 2013,19(26):4185-4191. Kreisel W, Ruf G, Salm R, et al. Protein-losing pseudomembranous colitis with cap polyposis-like features[J]. World J Gastroenterol, 2017,23(16):3003-3010. Shimizu K, Koga H, Iida M, et al. Does metronidazole cure cap polyposis by its antiinflammatory actions instead of by its antibiotic action? A case study[J]. Dig Dis Sci, 2002,47(7):1465-1468. Hizawa K, Iida M, Suekane H, et al. Mucosal prolapse syndrome: diagnosis with endoscopic US[J]. Radiology, 1994,191(2):527-530. Ng K H, Mathur P, Kumarasinghe M P, et al. Cap polyposis: further experience and review[J]. Dis Colon Rectum, 2004,47(7):1208-1215. Bordeianou L, Paquette I, Johnson E, et al. Clinical Practice Guidelines for the Treatment of Rectal Prolapse[J]. Dis Colon Rectum, 2017,60(11):1121-1131. Additional Declarations No competing interests reported. Supplementary Files supplementaryTableS1.docx 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. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-3921061","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":271017739,"identity":"22d35d10-f9a6-4431-9acf-ba5a5813326c","order_by":0,"name":"Lingyu Huang","email":"","orcid":"","institution":"Sun Yat-sen University","correspondingAuthor":false,"prefix":"","firstName":"Lingyu","middleName":"","lastName":"Huang","suffix":""},{"id":271017740,"identity":"6f2ebd61-a2a2-4694-9074-706bf2867900","order_by":1,"name":"Xiaoying Lou","email":"","orcid":"","institution":"Sun Yat-sen University","correspondingAuthor":false,"prefix":"","firstName":"Xiaoying","middleName":"","lastName":"Lou","suffix":""},{"id":271017741,"identity":"ea28e005-57f8-44b8-a10c-d7806a9af084","order_by":2,"name":"Chunyu Chen","email":"","orcid":"","institution":"Sun Yat-sen University","correspondingAuthor":false,"prefix":"","firstName":"Chunyu","middleName":"","lastName":"Chen","suffix":""},{"id":271017742,"identity":"d7f033ac-a5b6-4c5b-9ed4-480082956762","order_by":3,"name":"Yi Lu","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA90lEQVRIiWNgGAWjYBACPiA+IPnHhoGBmbkBJmiAVwsbSItlQxpQCyMJWhgqGw4DSaK1SOQYHri543w0fztjA+PPtrrEBvbmbRIMNXfwaTE4OPPM7dwZhxkbmHnbDic28Bwrk2A49gyvlsMSbLdzG0BaGNsOJDZI5JhJMIKdikfLH7ZzufMPwxwm/4awlgOSbQdyNwC1MPC2MQNt4SGghedZwQGJM8m5G4FaDvOcO2zcxpNWbJFwDLcWfvbkzR8kKuxy550/fPDhj7I62X72wxtvfKjBrYWBgQMRCwcY2aAxlYBHAwMD+wMkzh+8SkfBKBgFo2CEAgDf7Vfra54tQgAAAABJRU5ErkJggg==","orcid":"","institution":"Sun Yat-sen University","correspondingAuthor":true,"prefix":"","firstName":"Yi","middleName":"","lastName":"Lu","suffix":""}],"badges":[],"createdAt":"2024-02-02 13:47:19","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3921061/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3921061/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":50748487,"identity":"71cfb9b7-db04-452f-8e74-09bca1052c5c","added_by":"auto","created_at":"2024-02-06 17:16:12","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":931192,"visible":true,"origin":"","legend":"\u003cp\u003eColonoscopy images and surgery specimen of cap polyposis (CP): A-C, patient No. 30, colonoscopy images before and after medical treatments; D-F, patient No. 5, colonoscopy images showing endoscopic mucosal resection for endotherapy of CP; G-I, patient No. 11, with prolapse of CP, and was treated by surgery resection.\u003c/p\u003e","description":"","filename":"Figure11.png","url":"https://assets-eu.researchsquare.com/files/rs-3921061/v1/891cc5eb36531274d41a1201.png"},{"id":50748489,"identity":"081cc58a-15d2-4a53-84ad-c127b3333edb","added_by":"auto","created_at":"2024-02-06 17:16:12","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":1697248,"visible":true,"origin":"","legend":"\u003cp\u003ePathological findings (hematoxylin and eosin staining.): A. Prominent polypoid lesion seen covered by a cap of inflammatory granulation tissue (1X power); B. Inflammatory cells immersed and inflammatory granulation tissue (10X power); C. Goblet cell hyperplasia with serrated appearance, and cyst dilation with increased mucous secretion (10X power); D. In other cases, ischemic changes could be seen with crypt atrophy and interstitial fibrous tissue hyperplasia (4X power).\u003c/p\u003e","description":"","filename":"Figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-3921061/v1/0c23454e85efc6ae57fa3785.png"},{"id":50748488,"identity":"0cce0cf9-36fd-4bb2-b301-b73ca1dd66fa","added_by":"auto","created_at":"2024-02-06 17:16:12","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":84259,"visible":true,"origin":"","legend":"\u003cp\u003eKaplan-Meier curves showing the recurrence rates of endotherapy and surgery for the treatment of cap polyposis\u003c/p\u003e","description":"","filename":"Figure3.png","url":"https://assets-eu.researchsquare.com/files/rs-3921061/v1/9641d0af013e34d89f60c310.png"},{"id":51113245,"identity":"87f30a79-8a3e-4714-ad1e-045e878de4fd","added_by":"auto","created_at":"2024-02-14 10:27:52","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3715185,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3921061/v1/00ffe5e3-5fec-4b7a-a226-a6f68f5547ef.pdf"},{"id":50749257,"identity":"6cb14c52-75c3-4236-9cc0-0d3c9de51d1b","added_by":"auto","created_at":"2024-02-06 17:24:12","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":16384,"visible":true,"origin":"","legend":"","description":"","filename":"supplementaryTableS1.docx","url":"https://assets-eu.researchsquare.com/files/rs-3921061/v1/cb2f3c0e69b451c973bf921c.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Clinical, Endoscopic, Pathological Characteristics and Managements of Cap Polyposis: A Real-world Study from China","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eCap polyposis (CP) is a rare kind of benign disease, that is usually located in the rectum and sometimes in the colon or stomach \u003csup\u003e[\u003cspan additionalcitationids=\"CR2 CR3 CR4\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]\u003c/sup\u003e. It was first described by Williams et al. in 1985, and as the name implies, polyps have a \u0026ldquo;cap\u0026rdquo; formed by granulation tissue covered with fibrinopurulent exudates \u003csup\u003e[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/sup\u003e. The etiology of CP is still unclear and might be associated with mucosal prolapse, inflammation, infection with \u003cem\u003eHelicobacter pylori\u003c/em\u003e (\u003cem\u003eH. pylori\u003c/em\u003e) or other microorganisms, and dysbacteriosis \u003csup\u003e[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan additionalcitationids=\"CR7 CR8\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]\u003c/sup\u003e. The clinical manifestations of CP are constipation, diarrhea, abdominal pain, mucous stool, hematochezia, and hypoproteinemia \u003csup\u003e[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]\u003c/sup\u003e. Endoscopically, we can usually find multiple erythematous, sessile polyps covered by fibrinopurulent exudates of different sizes, and they are often located at the apices of the transverse mucosal folds with normal mucosa between the polyps. These characteristics help us to differentiate CP from inflammatory bowel disease (IBD) and cancer in endoscopy \u003csup\u003e[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]\u003c/sup\u003e. In imaging examinations, CP is sometimes misdiagnosed as cancer, and surgery might be subsequently suggested to the patient. Hence, improving the diagnostic accuracy before surgery is very important. There are a variety of therapies for CP, such as \u003cem\u003eH. pylori\u003c/em\u003e eradication, antibiotics, steroids, 5-amino salicylic acids (5-ASAs), infliximab, and endoscopic or surgical resection \u003csup\u003e[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]\u003c/sup\u003e. However, for now, no standard therapy has been recommended for CP, as sometimes the polyps are not resolved or reoccur \u003csup\u003e[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]\u003c/sup\u003e. The majority of the previously published articles on this issue are case reports or case series with a small number of patients; hence, we summarized the experience in our hospital to add more data, hoping to raise the physicians\u0026rsquo; and surgeons\u0026rsquo; awareness of this disease.\u003c/p\u003e"},{"header":"METHODS","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003ePatients\u003c/h2\u003e \u003cp\u003eFrom January, 1st, 2017 to November, 1st, 2021, consecutive patients diagnosed with CP in our hospital were retrospectively reviewed. The patients were identified from the pathology database in our hospital. The inclusion criteria were as follows: a. patients with confirmed CP, meaning the endoscopy showed multiple polyps covered by fibrinopurulent exudates, and pathology showed inflammatory polyps covered by a thick layer of fibrinopurulent exudate, forming the \u0026ldquo;cap\u0026rdquo; structure; and b. patients whose clinical information could be obtained. The exclusion criteria were as follows: a. foreigners; b. patients without endoscopic pictures; c. patients that did not receive any treatment in our hospital; d. patients with IBD; and e. patients with parastomal polyps.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eInformation collected\u003c/h2\u003e \u003cp\u003eThe following information was collected in our electronic medical records: age, gender, symptoms, medical histories, laboratory tests [mainly hemoglobin, platelet, white blood cell, neutrophils, serum albumin (ALB), high sensitivity C reactive protein (hs-CRP)], imaging results [contrast-enhanced abdominal computed tomography (CT) or magnetic resonance imaging (MRI)], endoscopic findings (mainly gastroduodenoscopy and ileocolonoscopy), rectum ultrasound, pathology results, final diagnosis, and treatments of the patients. We made telephone calls to the patients and searched for the information in our electronic medical records to obtain the follow-up results of the patients.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eStatistical Analysis\u003c/h2\u003e \u003cp\u003eIBM SPSS Statistics Version 22 was used to perform the statistical analyses. Continuous variables with normal distribution are presented as mean (standard deviation, SD), and those without normal distribution are presented as median (interquartile range, IQR). Categorical variables were expressed as numbers (percentages), and they were tested by using the χ\u003csup\u003e2\u003c/sup\u003e test. To compare the recurrence rates and time of endotherapy and surgical resection, we used the Kaplan‒Meier method to analyze the recurrence results. The endpoint was defined as the first recurrence since endotherapy/surgical resection, and recurrence was defined as polyps recurred in endoscopy or in digital rectal examination, or symptoms appeared again (as not all patients had endoscopy reexamination).\u003c/p\u003e \u003c/div\u003e"},{"header":"RESULTS","content":"\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eBasic information, laboratory, imaging and endoscopic characteristics\u003c/h2\u003e \u003cp\u003eWe chose 41 patients with CP for final analysis, among whom, 7 patients had received endotherapy or surgery in other hospitals before. The basic information, laboratory results, and imaging characteristics of the patients are presented in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eBasic information, laboratory and imaging characteristics\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eResults\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSex, M (n, %)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e37 (90.24%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge, years (median, IQR)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e20 (14)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSymptoms (n, %)\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHematochezia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e29 (70.73%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIncreased stool frequency\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5 (12.20%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDifficult defecation or constipation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5 (12.20%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProlapse of mass\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e15 (36.59%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTenesmus\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7 (17.07%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAbdominal pain\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4 (9.76%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDiarrhea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 (7.32%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo symptom\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4 (9.76%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDisease course, months (median, IQR)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12 (33)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLaboratory Results (n, %)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAnemia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8 (19.51%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eThrombocytosis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e16 (39.02%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLeukocytosis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (2.44%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eElevated hs-CRP\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 (3/36, 8.33%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePositive 13 C urea breath test\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8 (8/13, 61.54%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePositive serum antibody of \u003cem\u003eH. pylori\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0/8, 0)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eImaging Results (n, %)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eContrast-enhanced abdominal CT\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBenign lesions\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10 (10/19, 52.63%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMalignant lesions\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5 (5/19, 26.32%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eUnclear\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 (3/19, 15.79%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNormal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (1/19, 5.26%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eContrast-enhanced abdominal MRI\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBenign lesions\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e19 (19/22, 86.36%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMalignant lesions\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 (3/19, 13.64%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"2\"\u003eIQR: interquartile range; hs-CRP, high sensitivity C reactive protein; CT, computed tomography; MRI, magnetic resonance imaging\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"2\"\u003eAnemia: hemoglobin\u0026thinsp;\u0026lt;\u0026thinsp;120g/L for male and \u0026lt;\u0026thinsp;11g/L for female; thrombocytosis: platelet\u0026thinsp;\u0026gt;\u0026thinsp;3*10^9/L; leukocytosis: white blood cell\u0026thinsp;\u0026gt;\u0026thinsp;10*10^9/L; elevated hs-CRP: hs-CRP\u0026thinsp;\u0026gt;\u0026thinsp;3mg/L.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"2\"\u003e* some patients had more than one symptom\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eIn endoscopic findings, multiple erythematous, polyps covered by rich exudates of different sizes were frequently found (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). For 22 patients, the involved site was the rectum alone, and for another 19 patients, both the anus and rectum were involved. In 11 patients, the number of polyps was less than 5, while for others, the number of polyps was \u0026ge;\u0026thinsp;5. Pathological findings showed polyps covered with fibrous purulent exudates and inflammatory granulation tissue forming a \u0026ldquo;cap\u0026rdquo; structure, with crypt dilatation and mucous oversecretion within the crypts; ischemic changes with crypt atrophy and interstitial fibrous tissue hyperplasia mimicking rectal prolapse could also be observed (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eTreatments and follow-up results\u003c/h2\u003e \u003cp\u003eAs no standard therapy has been recommended for CP, there were multiple and combined treatments for these patients. These treatments can be mainly divided into 3 categories: medical therapy (including observation, \u003cem\u003eH. pylori\u003c/em\u003e eradication, corticoids enema, oral metronidazole, mesalazine anal plug/enema/oral, and biofeedback therapy), endotherapy [including polypectomy with snare, and endoscopic mucosal resection (EMR)], and surgery (including transanal polypectomy, laparoscopic rectum resection, and laparoscopic rectal fixation). The explicit details are presented in the supplementary Table \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003eFrom the follow-up results, we found that medical therapy could help to diminish the size of the polyps but was difficult to resolve (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eC); however, the patients\u0026rsquo; symptoms could be resolved. Twenty-three patients received surgical resection and 12 patients received endotherapy. We further compared their efficacy and safety. Both could resolve the polyps, but with high recurrence. Endotherapy and surgery were both safe, and the mortality was 0. Only 1 patient (8.33%) who received endoscopic polypectomy with snare was complicated with slight bleeding, and emergent colonoscopy found no signs of active bleeding; 1 patient (4.35%) who received transanal\u0026thinsp;+\u0026thinsp;laparoscopic partial rectum resection had anastomotic leakage, and was treated by conservative methods; another 1 patient (4.35%) who received laparoscopic partial rectum resection\u0026thinsp;+\u0026thinsp;ileostomy had anastomotic stricture, and was treated by endoscopic stricture dilation and incision.\u003c/p\u003e \u003cp\u003eThe patients who received polyp resection were followed for a median of 26 (IQR 19) months (1 patient who received surgical resection was lost). Eighteen patients (51.43%) had recurrence, and the recurrence rate was not significantly different between endotherapy and surgical resection (41.67% vs. 59.09% P\u0026thinsp;=\u0026thinsp;0.331). Kaplan‒Meier curves (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e) further supported that, the recurrence risk was not significantly different between the two kinds of therapy (P\u0026thinsp;=\u0026thinsp;0.321).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003eLiterature review\u003c/h2\u003e \u003cp\u003eWe also summarized the literature on this issue \u003csup\u003e[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan additionalcitationids=\"CR15 CR16 CR17 CR18\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]\u003c/sup\u003e, and evaluated the percentage of clinical improvement of these treatments (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eEfficacy Ratio by Treatment in the Previously Published Cases\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTreatments\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eEffective cases/ total cases\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eEfficacy ratio(%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eObservation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6/7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e85.7\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAvoiding straining at defecation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2/5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal parental nutrition\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0/5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMetronidazole \u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7/22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e31.8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eQuinolone\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0/2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSteroids (oral)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2/17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11.8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSteroids (enema or suppo)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4/15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e26.7\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAminosalicylates (oral)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0/24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAminosalicylates (enema or suppo)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1/4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e25\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eHelicobacter pylori\u003c/em\u003e eradication \u003csup\u003e#\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e15/16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e93.8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eInfliximab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2/5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eResection (endoscopic or surgical)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23/37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e62.2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"3\"\u003e*1effective case used metronidazole\u0026thinsp;+\u0026thinsp;amoxicillin;\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"3\"\u003e#1 effective case combined steroids oral and enema, and 1 case failed was \u003cem\u003eH. pylori\u003c/em\u003e negative.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eCP is a relatively rare disease that is still not well recognized by physicians and surgeons, and currently, fewer than 100 cases have been published in the literature \u003csup\u003e[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]\u003c/sup\u003e. In our study, most of the patients were very young, their median age was only 20 years old, and some of them were annoyed by this disease affecting their normal work and study status. Hence, we thought we should pay more attention to this disease. Here we shared the experience in our hospital to add more data.\u003c/p\u003e \u003cp\u003eThe majority of the patients were male, which was in accordance with previous literature \u003csup\u003e[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]\u003c/sup\u003e. In 2012, Papaconstantinou et al. summarized the cases of CP \u003csup\u003e[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]\u003c/sup\u003e, and most of the patients were older than 50 years of age, but later, Brunner et al. summarized that children or younger populations also would develop CP \u003csup\u003e[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]\u003c/sup\u003e. The laboratory, and imaging characteristics of CP were not that specific. A portion of them would have anemia and thrombocytosis, while leukocytosis or elevated hs-CRP was not that common. Additionally, we should be aware that a certain number of patients would be misdiagnosed with malignant lesions in contrast-enhanced CT or MRI, in which the rates were 26.32% and 13.64%, respectively. Rectal cancer usually presents as a mass and seldomly multiple polyps (unless familial adenomatous polyposis), and repeated biopsy does not support malignant changes. If differentiation is still difficult, then a large piece of the polyp should be resected to help make a diagnosis.\u003c/p\u003e \u003cp\u003eIBD is also an important differential diagnosis, especially in children: it was the initial diagnosis in 75% of the reports on children \u003csup\u003e[\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]\u003c/sup\u003e. However, endoscopically, ulcerative colitis has background mucous change, while CP is usually characterized by multiple polyps covered by fibrinopurulent exudates with normal mucosa between the polyps, and they have different pathologic features.\u003c/p\u003e \u003cp\u003eThe relationship between CP and mucosal prolapse syndrome (MPS) is still debated. Some patients with CP have symptoms of prolapse. Cambell et al. supposed that abnormal colonic motility may lead to prolapse of the mucosa at the apices of transverse mucosal folds and cause ischemic changes \u003csup\u003e[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]\u003c/sup\u003e. The pathology includes fibromuscular obliteration of the lamina propria, granulation tissue, and elongated, hyperplastic glands. These features can also appear in MPS. However, they have some differences. First, fibromuscular obliteration is more marked in cap polyposis; second, CP can be found in both the colon and rectum, while MPS is usually confined to the rectum; third, the two diseases have different endoscopic ultrasound sonography images, as CP shows significant thickening of the mucosa, whereas MPS has remarkable thickening of the submucous \u003csup\u003e[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eTo date, there is no standard or optimal therapy for CP, as its cause remains unclear. On the strength of previously published literature, various kinds of treatments have been tried, including medical therapies (observation, steroids, aminosalicylates, infliximab, metronidazole, \u003cem\u003eH. pylori\u003c/em\u003e eradication, and so on), and endoscopic and surgical resection. But the clinical outcomes were heterogeneous. Some patients had spontaneous remission, while some needed surgical resection and still experienced recurrence \u003csup\u003e[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]\u003c/sup\u003e. Some investigators believed that, in adults, polypectomy should be performed to alleviate symptoms. However, in children, medical treatments were preferred. If the disease persists or recurs with medical treatment, then we should consider resection \u003csup\u003e[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]\u003c/sup\u003e. In our study, we further compared the long-term effectiveness of endotherapy and surgical resection, although with a small number of patients, we found that, the recurrence risk had no significant difference. However, we combined several different means of endotherapy or surgical resection in the analysis, and we think that if we could accumulate more patients, then maybe we can find a certain means of resection with the best short-term and long-term outcomes.\u003c/p\u003e \u003cp\u003eBased on the literature review\u003csup\u003e[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan additionalcitationids=\"CR15 CR16 CR17 CR18\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]\u003c/sup\u003e and our own data, we thought that, if the patient was \u003cem\u003eH. pylori\u003c/em\u003e positive, then \u003cem\u003eH. pylori\u003c/em\u003e eradication combined with other therapies might be useful. There were 7 patients who were tested to have \u003cem\u003eH. pylori\u003c/em\u003e, 5 of them had improvement after \u003cem\u003eH. pylori\u003c/em\u003e eradication, the other two was lost. \u003cem\u003eH. pylori\u003c/em\u003e negative, although various means tried, the outcome was not that good. Moreover, for those with rectal prolapse, if the situation of rectal prolapse was not treated, then CP seemed to recur repeatedly.\u003c/p\u003e \u003cp\u003eThe goal of CP treatment is another question that we need to consider. During follow-up, some patients might have no symptoms, but the colonoscopy still showed polyps with smaller sizes (or recurrence of polyps). They felt very well, and did not want to see the doctors for further treatment at the moment. Should the patients receive treatments until the disappearance of all the polyps, until the disappearance of all the symptoms or until the symptoms do not influence the patient\u0026rsquo;s work and life? The above questions remain to be answered. The natural course of CP is largely unknown, and if asymptomatic or slightly symptomatic CP is left untreated, the chance and risk of developing malignant lesions are also unknown. In this study, no malignant lesions were observed during follow-up. In the future, if we can obtain more information on the abovementioned aspects, we will decide the goal of CP treatment and the follow-up strategy\u003c/p\u003e \u003cp\u003eThere are some limitations in this study. First, due to the rarity of CP, it was very difficult to conduct a prospective, large sample-sized study, so we only retrospectively reviewed the clinical data of these patients, and because of the real world setting and the retrospective nature of the study, the treatment options were not chosen following a preestablished algorithm, and the pre-treatment conditions was hard to evaluate in different groups. Second, as no standard therapy for CP is recommended, the treatments varied greatly in different patients, and even in the same patients but in different periods; moreover, sometimes combined treatments were used. It was very difficult to simply generalize these therapies into several kinds and evaluate their efficacy. Third, as not all patients received colonoscopy during follow-up, in this study, recurrence was defined as polyps recurred in endoscopy or digital rectal examination, or symptoms appeared again. However, in some patients, they might have no symptoms, but colonoscopy would show polyp recurrence. If we defined recurrence as polyps recurred in endoscopy, then the recurrence rates in this study were underestimated. \u003csup\u003e[\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]\u003c/sup\u003e\u003c/p\u003e \u003cp\u003eIn conclusion, CP is a disease with an increasing incidence rate that is affecting mostly young males and it easily recurs. Endoscopic and imaging features can mimic IBD or rectal cancer, and their relationship with MPS is still under debate. The clinical improvement of medical treatments was not satisfactory and was inconsistent. Endotherapy or surgical resection could remove the polyposis and provide temporary relief, but the recurrence rates were high, with no difference between the two methods.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study protocol was approved by the Institutional Review Board (IRB) of The Sixth Affiliated Hospital, Sun Yat-sen University, and the requirement for signed informed consent was waived by the IRB. The approval number was 2021ZSLYEC-455 and the approval date was November 22, 2021. All methods were performed in accordance with the relevant guidelines and regulations.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding Declaration\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was supported by The Sixth Affiliated Hospital of Sun Yat-Sen University Clinical Research- \u0026ldquo;1010\u0026rdquo; Program, the program of Guangdong Provincial Clinical Research Center for Digestive Diseases (2020B1111170004), and National Key Clinical Discipline.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Interest declaration\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors contribution\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eLingyu Huang collected the data, performed the statistical analysis and wrote the manuscript draft. Xiaoying Lou collected the data, pathological images, and performed the statistical analysis. Chunyu Chen collected the data. Yi Lu designed the study, wrote and revised the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used are available from the corresponding author on reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eOiya H, Okawa K, Aoki T, et al. Cap polyposis cured by Helicobacter pylori eradication therapy[J]. J Gastroenterol, 2002,37(6):463-466.\u003c/li\u003e\n\u003cli\u003eBrunner M, Agaimy A, Atreya R, et al. Cap polyposis in children: case report and literature review[J]. International journal of colorectal disease, 2019,34(2):363-368.\u003c/li\u003e\n\u003cli\u003eEsaki M, Matsumoto T, Kobayashi H, et al. Cap polyposis of the colon and rectum: an analysis of endoscopic findings[J]. Endoscopy, 2001,33(3):262-266.\u003c/li\u003e\n\u003cli\u003eGT W, HJR B, BC M. Inflammatory cap polyps of the large intestine [abstract][J]. Br J Surg, 1985,72(Suppl):133.\u003c/li\u003e\n\u003cli\u003eDa C A R, Castanheira A, Silva A. Unusual colon polyps. Diagnosis: Cap polyposis[J]. Gastroenterology, 2011,141(4):e1-e2.\u003c/li\u003e\n\u003cli\u003eSuzuki H, Sato M, Akutsu D, et al. A case of cap polyposis remission by betamethasone enema after antibiotics therapy including Helicobacter pylori eradication[J]. Journal of gastrointestinal and liver diseases : JGLD, 2014,23(2):203-206.\u003c/li\u003e\n\u003cli\u003eMurata M, Sugimoto M, Ban H, et al. Cap polyposis refractory to Helicobacter pylori eradication treated with endoscopic submucosal dissection[J]. World J Gastrointest Endosc, 2017,9(10):529-534.\u003c/li\u003e\n\u003cli\u003eKonishi T, Watanabe T, Takei Y, et al. Cap polyposis: an inflammatory disorder or a spectrum of mucosal prolapse syndrome?[J]. Gut, 2005,54(9):1342-1343.\u003c/li\u003e\n\u003cli\u003eOkamoto K, Watanabe T, Komeda Y, et al. Dysbiosis-Associated Polyposis of the Colon-Cap Polyposis[J]. Frontiers in immunology, 2018,9:918.\u003c/li\u003e\n\u003cli\u003eCampbell A P, Cobb C A, Chapman R W, et al. Cap polyposis--an unusual cause of diarrhoea[J]. Gut, 1993,34(4):562-564.\u003c/li\u003e\n\u003cli\u003eOshitani N, Moriyama Y, Matsumoto T, et al. Protein-losing enteropathy from cap polyposis[J]. Lancet, 1995,346(8989):1567.\u003c/li\u003e\n\u003cli\u003eAggarwal A, Lang A, Krigman H R, et al. Vascular Malformation and CAP Polyposis: A New Insight into Pathophysiology or Fortuitous Association?[J]. Fetal Pediatr Pathol, 2021:1-6.\u003c/li\u003e\n\u003cli\u003eMaunoury V, Breisse M, Desreumaux P, et al. Infliximab failure in cap polyposis[J]. Gut, 2005,54(2):313-314.\u003c/li\u003e\n\u003cli\u003eMonsalve A S, Miranda G P, Santander V C. Endoscopic mucosal resection for cap poliposis treatment[J]. Rev Esp Enferm Dig, 2020,112(2):155.\u003c/li\u003e\n\u003cli\u003eTamura K, Matsuda K, Yokoyama S, et al. Successful laparoscopic resection for cap polyposis: case report, literature review[J]. Surgical case reports, 2018,4(1):69.\u003c/li\u003e\n\u003cli\u003eAnuchapreeda S, Phengsuthi P, Aumpansub P, et al. Polypectomy for Recurrent Inflammatory Cap Polyposis Combined with Argon Plasma Coagulation[J]. ACG Case Rep J, 2018,5:e35.\u003c/li\u003e\n\u003cli\u003eKim S C, Kang M J, Jeong Y J, et al. A Case of Cap Polyposis with Epidermal Nevus in an Infant[J]. J Korean Med Sci, 2017,32(5):880-884.\u003c/li\u003e\n\u003cli\u003eBatra S, Johal J, Lee P, et al. Cap Polyposis Masquerading as Inflammatory Bowel Disease in a Child[J]. J Pediatr Gastroenterol Nutr, 2018,67(3):e57.\u003c/li\u003e\n\u003cli\u003eArana R, Fl\u0026eacute;jou J F, Parc Y, et al. Cap polyposis and colitis cystica profunda: a rare association[J]. Histopathology, 2014,64(4):604-607.\u003c/li\u003e\n\u003cli\u003ePapaconstantinou I, Karakatsanis A, Benia X, et al. Solitary rectal cap polyp: Case report and review of the literature[J]. World J Gastrointest Surg, 2012,4(6):157-162.\u003c/li\u003e\n\u003cli\u003eLi J H, Leong M Y, Phua K B, et al. Cap polyposis: a rare cause of rectal bleeding in children[J]. World J Gastroenterol, 2013,19(26):4185-4191.\u003c/li\u003e\n\u003cli\u003eKreisel W, Ruf G, Salm R, et al. Protein-losing pseudomembranous colitis with cap polyposis-like features[J]. World J Gastroenterol, 2017,23(16):3003-3010.\u003c/li\u003e\n\u003cli\u003eShimizu K, Koga H, Iida M, et al. Does metronidazole cure cap polyposis by its antiinflammatory actions instead of by its antibiotic action? A case study[J]. Dig Dis Sci, 2002,47(7):1465-1468.\u003c/li\u003e\n\u003cli\u003eHizawa K, Iida M, Suekane H, et al. Mucosal prolapse syndrome: diagnosis with endoscopic US[J]. Radiology, 1994,191(2):527-530.\u003c/li\u003e\n\u003cli\u003eNg K H, Mathur P, Kumarasinghe M P, et al. Cap polyposis: further experience and review[J]. Dis Colon Rectum, 2004,47(7):1208-1215.\u003c/li\u003e\n\u003cli\u003eBordeianou L, Paquette I, Johnson E, et al. Clinical Practice Guidelines for the Treatment of Rectal Prolapse[J]. Dis Colon Rectum, 2017,60(11):1121-1131.\u003c/li\u003e\n\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":"Cap polyposis, Helicobacter pylori, treatment, colonoscopy, resection","lastPublishedDoi":"10.21203/rs.3.rs-3921061/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3921061/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground and aims:\u003c/h2\u003e \u003cp\u003eCap polyposis (CP) is a rare kind of benign disease, and the majority of previously published articles on it involve a small number of patients. Hence, we summarized our experience to add more data, hoping to raise awareness of this disease.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eFrom January, 1st, 2017 to November, 1st, 2021, consecutive patients diagnosed with CP were retrospectively reviewed. Their medical histories, and laboratory, imaging, endoscopic, and pathology results were analyzed. We made telephone calls to the patients and searched for the information in our electronic medical records to obtain the follow-up results.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eForty-one patients were chosen for analysis. The median age of the patients was 20 years old, and 90.24% (37 patients) of the patients were male. There were multiple and combined treatments for these patients. These treatments can be mainly divided into 3 categories: medical therapy, endotherapy and surgery. Medical therapy could help to diminish the size of the polyps but was difficult to resolve; however, the patients\u0026rsquo; symptoms could be diminished. Twenty-three patients received surgical resection, and 12 patients received endotherapy. We further compared the two methods of polyp resection. Both endotherapy and surgery were safe, and the recurrence risk was not significantly different between the two kinds of therapy (P\u0026thinsp;=\u0026thinsp;0.321).\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eThe clinical improvement of medical treatments was not satisfactory, and endotherapy or surgical resection could remove the polyposis and provide temporary relief, but the recurrence rates were high.\u003c/p\u003e","manuscriptTitle":"Clinical, Endoscopic, Pathological Characteristics and Managements of Cap Polyposis: A Real-world Study from China","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-02-06 17:16:07","doi":"10.21203/rs.3.rs-3921061/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":"5e39e9aa-6da6-4ddd-b0f8-073b16023938","owner":[],"postedDate":"February 6th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-02-14T10:19:43+00:00","versionOfRecord":[],"versionCreatedAt":"2024-02-06 17:16:07","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-3921061","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3921061","identity":"rs-3921061","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}