A Rare Cause of Pelvic Mass: Presacral Giant Schwannoma – A Case Report

A Rare Cause of Pelvic Mass: Presacral Giant Schwannoma – A Case Report | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Case Report A Rare Cause of Pelvic Mass: Presacral Giant Schwannoma – A Case Report Candost Hanedan, Neslihan Öztürk, Berna Turhan, İnan Uzunoğlu This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8007200/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:Presacral schwannomas are extremely rare benign tumors arising from Schwann cells of peripheral nerves. Their deep pelvic location poses significant diagnostic and surgical challenges due to proximity to critical neurovascular structures. Case presentation:We present a case of a 57-year-old postmenopausal woman with a large presacral schwannoma successfully managed through complete surgical excision using a multidisciplinary approach. During the preoperative evaluation, MRI suggested possible local invasion, leading to a joint operation with the neurosurgery team. This collaboration enabled safe dissection and complete tumor removal while minimizing neurological risks. Conclusion: This case underscores the importance of detailed preoperative imaging, intraoperative neuromonitoring, and multidisciplinary collaboration for achieving optimal outcomes in the management of presacral schwannomas. Presacral schwannoma Pelvic mass Retrorectal tumor Schwann cell tumor Multidisciplinary surgery Intraoperative neuromonitoring Figures Figure 1 Figure 2 Introduciton Schwannomas or neurilemmomas develop from Schwann cells which maintain their differentiation to become the most prevalent benign peripheral nerve tumors of nerve tissue [1]. These tumors show minimal growth while remaining symptom-free in most cases. The development of malignant cells in schwannomas occurs rarely and scientists link this process to von Recklinghausen's disease [neurofibromatosis type 1] or previous radiation exposure [2]. The diagnosis of this condition depends on histopathological and immunohistochemical tests which show Schwannian cell differentiation[3]. Schwannomas develop from peripheral nerves and cranial nerves and visceral nerves and researchers have documented their occurrence at different body locations [4]. The prevalence of pelvic schwannomas remains extremely low because they represent less than 0.3% to 3.2% of all schwannomas and less than 0.4% to 15% of retrorectal tumors. The sacral region contains the least number of schwannomas among all locations [5,6]. The Klimo classification system divides sacral schwannomas into three types based on their location: Type I [confined to the sacrum] and Type II [extending past the sacral osseous borders] and Type III [located in the presacral space] [7]. The evaluation of neoplasm size and anatomical relationships and potential complications such as hemorrhage or nerve damage requires preoperative imaging through CT or MRI scans to create effective surgical plans and reduce operational risks. [8]. Our tertiary center successfully treated a giant presacral schwannoma through surgical intervention. The case demonstrates how complete preoperative radiological assessment enables successful surgical management of schwannomas located in complex anatomical areas including the presacral space. Case Presentation A 57-year-old woman who had reached menopause received a referral to our tertiary medical facility during November 2022 because she experienced abnormal menstrual bleeding and doctors detected a pelvic mass through abdominal CT imaging. The pelvic examination showed a fixed solid mass that filled the abdominal area without any signs of neurological symptoms including radicular pain. The ultrasound results showed a myomatous uterus and normal ovaries and a solid cystic mass that spread throughout the abdominal area. All tumor marker results and laboratory test results fell within normal ranges. The mass position required pelvic MRI evaluation to assess its relationship with vital structures in the area. The patient had no medical conditions and no family history of diseases. The mass received its diagnosis as a type 3 pelvic schwannoma from expert radiologists who analyzed the MRI results [Figure 1]. The patient underwent normal results from her preoperative cervical smear and endometrial biopsy [pipelle curettage] because she underwent simultaneous hysterectomy. The medical team consisting of neurosurgeons and radiologists conducted a preoperative evaluation of the case. The surgical team performed a joint procedure because the mass required access from the front side. The surgical team performed an exploratory laparotomy to find a 15×12 cm presacral mass which seemed to stem from the sacrum while filling the abdominal space. The surgical team found a myomatous uterus together with standard adnexal structures during the procedure. The team performed bilateral retroperitoneal access to protect the ureters while they suspended them for protection. The surgical team accessed the retrorectal space to create dissection paths which allowed them to move the rectosigmoid colon to the side. The team took precautions to prevent major bleeding by suspending all major blood vessels. The left internal iliac artery suffered a 400 cc bleeding incident because the tumor had penetrated through its walls during surgical dissection. The medical team achieved successful hemostasis through artery ligation [Figure 2]. The neurosurgery team used intraoperative neuromonitoring to monitor the tumor's relationship with sacral nerve roots during the procedure. The monitoring system detected S1-S2 root neural signals during dissection so the team proceeded with tumor removal without any neurological issues during surgery.The surgical team performed a total hysterectomy and bilateral salpingo-oophorectomy after tumor debulking. The postoperative period showed no major bleeding and the drainage tube got removed on the third day after surgery. The patient left the hospital on the fourth day after surgery without showing any neurological problems. The surgical tissue examination showed no abnormal cell growth or dead tissue. The patient showed no symptoms during the 34-month follow-up period and the MRI scan revealed no signs of remaining or recurring disease. Discussion Schwannomas that develop in the presacral area represent rare benign tumors which stem from Schwann cells but make up only a small portion of all schwannomas and show rare occurrence in sacral and retrorectal areas. The tumors maintain their benign nature but their deep pelvic location makes surgical and diagnostic procedures extremely difficult because they surround vital neurovascular structures and surrounding pelvic tissues [9] The standard treatment for pelvic schwannomas involves complete surgical excision. [10]. Although these tumors are typically single, well-encapsulated, and non-invasive to surrounding tissues, their deep pelvic location necessitates thorough preoperative evaluation. As they enlarge, pelvic schwannomas may cause pelvic pain, urinary disturbances, or lower extremity swelling, while their proximity to critical structures increases the risk of surgical complications. Therefore, advanced preoperative imaging is essential to accurately determine the tumor’s location, its relationship to nearby neural and vascular tissues, and to optimize surgical planning for safe and effective removal. The diagnostic evaluation for abnormal uterine bleeding revealed a large 15×12 cm presacral schwannoma which was discovered incidentally. The tumor followed the common schwannoma pattern by staying without any neurological effects during its development. The MRI scans helped doctors identify the tumor and create surgical plans and they used the images to determine the Klimo type III classification according to Maghrebi et al. [11]. The surgical team used a combined approach between gynecological and neurosurgical experts to remove the tumor through an open abdominal procedure because of its large size and deep location. The surgical team used intraoperative neuromonitoring to track neural activity throughout the procedure which led to successful tumor extraction without nerve damage and validated the monitoring system's effectiveness for sacral nerve plexus surgeries [12]. The medical community continues to discuss the need for radiation therapy in benign schwannoma cases but most experts agree that it should only be used when pathological results show malignant or atypical tissue. The patient received no additional oncological treatment because the surgical team removed the tumor completely and pathological tests showed no signs of atypical cells or tissue death. The patient stayed free of symptoms during the 34-month monitoring period while MRI scans showed no signs of tumor persistence or recurrence which supports previous research showing that complete tumor removal leads to excellent prognosis with low recurrence rates [13]. Conclusions Complete surgical excision with careful multidisciplinary planning and intraoperative neuromonitoring ensures excellent outcomes in presacral schwannomas. This case contributes to the limited literature on pelvic schwannomas in women and underscores the value of collaborative surgical management. Declarations Patient Perspective The patient expressed satisfaction with the outcome, reporting complete relief of symptoms and gratitude for the multidisciplinary approach to her care. Consent for Publication Written informed consent for treatment and publication of this case and accompanying images was obtained from the patient. Competing Interests The authors declare that they have no competing interests. Funding The authors received no financial support for the research, authorship, or publication of this article. Authors’ Contributions Concept and design: Candost Hanedan, Neslihan Öztürk Data acquisition and analysis: Candost Hanedan, Neslihan Öztürk, Berna Turhan, İnan Uzunoğlu Manuscript drafting: Candost Hanedan, Neslihan Öztürk, Berna Turhan, İnan Uzunoğlu Critical revision: Candost Hanedan, Neslihan Öztürk Supervision: Candost Hanedan All authors read and approved the final manuscript. Additional Declarations No competing interests reported. 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1","display":"","copyAsset":false,"role":"figure","size":1168467,"visible":true,"origin":"","legend":"\u003cp\u003eSee image above for figure legend\u0026nbsp;\u003c/p\u003e","description":"","filename":"figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-8007200/v1/b526518d57591e5aa8db6fc2.png"},{"id":96615737,"identity":"63404b76-89a6-47ef-9311-0a9234f094c7","added_by":"auto","created_at":"2025-11-24 10:19:26","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":4252610,"visible":true,"origin":"","legend":"\u003cp\u003eSee image above for figure legend\u0026nbsp;\u003c/p\u003e","description":"","filename":"figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-8007200/v1/f9af5955d90c0c1e6b3a3296.png"},{"id":99313912,"identity":"f75fbb92-3896-4350-8b43-e42f4aeaec3c","added_by":"auto","created_at":"2025-12-31 16:20:36","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":7023263,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8007200/v1/d73b2e72-d4b9-47a7-8fc1-1263068da3a9.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"A Rare Cause of Pelvic Mass: Presacral Giant Schwannoma – A Case Report","fulltext":[{"header":"Introduciton","content":"\u003cp\u003eSchwannomas or neurilemmomas develop from Schwann cells which maintain their differentiation to become the most prevalent benign peripheral nerve tumors of nerve tissue [1]. These tumors show minimal growth while remaining symptom-free in most cases. The development of malignant cells in schwannomas occurs rarely and scientists link this process to von Recklinghausen's disease [neurofibromatosis type 1] or previous radiation exposure [2]. The diagnosis of this condition depends on histopathological and immunohistochemical tests which show Schwannian cell differentiation[3].\u003c/p\u003e\u003cp\u003eSchwannomas develop from peripheral nerves and cranial nerves and visceral nerves and researchers have documented their occurrence at different body locations [4]. The prevalence of pelvic schwannomas remains extremely low because they represent less than 0.3% to 3.2% of all schwannomas and less than 0.4% to 15% of retrorectal tumors. The sacral region contains the least number of schwannomas among all locations [5,6]. The Klimo classification system divides sacral schwannomas into three types based on their location: Type I [confined to the sacrum] and Type II [extending past the sacral osseous borders] and Type III [located in the presacral space] [7].\u003c/p\u003e\u003cp\u003eThe evaluation of neoplasm size and anatomical relationships and potential complications such as hemorrhage or nerve damage requires preoperative imaging through CT or MRI scans to create effective surgical plans and reduce operational risks. [8].\u003c/p\u003e\u003cp\u003eOur tertiary center successfully treated a giant presacral schwannoma through surgical intervention. The case demonstrates how complete preoperative radiological assessment enables successful surgical management of schwannomas located in complex anatomical areas including the presacral space.\u003c/p\u003e"},{"header":"Case Presentation","content":"\u003cp\u003eA 57-year-old woman who had reached menopause received a referral to our tertiary medical facility during November 2022 because she experienced abnormal menstrual bleeding and doctors detected a pelvic mass through abdominal CT imaging. The pelvic examination showed a fixed solid mass that filled the abdominal area without any signs of neurological symptoms including radicular pain. The ultrasound results showed a myomatous uterus and normal ovaries and a solid cystic mass that spread throughout the abdominal area. All tumor marker results and laboratory test results fell within normal ranges.\u003c/p\u003e\u003cp\u003eThe mass position required pelvic MRI evaluation to assess its relationship with vital structures in the area. The patient had no medical conditions and no family history of diseases. The mass received its diagnosis as a type 3 pelvic schwannoma from expert radiologists who analyzed the MRI results [Figure 1].\u003c/p\u003e\u003cp\u003eThe patient underwent normal results from her preoperative cervical smear and endometrial biopsy [pipelle curettage] because she underwent simultaneous hysterectomy. The medical team consisting of neurosurgeons and radiologists conducted a preoperative evaluation of the case. The surgical team performed a joint procedure because the mass required access from the front side.\u003c/p\u003e\u003cp\u003eThe surgical team performed an exploratory laparotomy to find a 15×12 cm presacral mass which seemed to stem from the sacrum while filling the abdominal space. The surgical team found a myomatous uterus together with standard adnexal structures during the procedure. The team performed bilateral retroperitoneal access to protect the ureters while they suspended them for protection. The surgical team accessed the retrorectal space to create dissection paths which allowed them to move the rectosigmoid colon to the side. The team took precautions to prevent major bleeding by suspending all major blood vessels.\u003c/p\u003e\u003cp\u003eThe left internal iliac artery suffered a 400 cc bleeding incident because the tumor had penetrated through its walls during surgical dissection. The medical team achieved successful hemostasis through artery ligation [Figure 2]. The neurosurgery team used intraoperative neuromonitoring to monitor the tumor's relationship with sacral nerve roots during the procedure. The monitoring system detected S1-S2 root neural signals during dissection so the team proceeded with tumor removal without any neurological issues during surgery.The surgical team performed a total hysterectomy and bilateral salpingo-oophorectomy after tumor debulking. The postoperative period showed no major bleeding and the drainage tube got removed on the third day after surgery. The patient left the hospital on the fourth day after surgery without showing any neurological problems.\u003c/p\u003e\u003cp\u003eThe surgical tissue examination showed no abnormal cell growth or dead tissue. The patient showed no symptoms during the 34-month follow-up period and the MRI scan revealed no signs of remaining or recurring disease.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eSchwannomas that develop in the presacral area represent rare benign tumors which stem from Schwann cells but make up only a small portion of all schwannomas and show rare occurrence in sacral and retrorectal areas. The tumors maintain their benign nature but their deep pelvic location makes surgical and diagnostic procedures extremely difficult because they surround vital neurovascular structures and surrounding pelvic tissues [9]\u003c/p\u003e\u003cp\u003eThe standard treatment for pelvic schwannomas involves complete surgical excision. [10]. Although these tumors are typically single, well-encapsulated, and non-invasive to surrounding tissues, their deep pelvic location necessitates thorough preoperative evaluation. As they enlarge, pelvic schwannomas may cause pelvic pain, urinary disturbances, or lower extremity swelling, while their proximity to critical structures increases the risk of surgical complications. Therefore, advanced preoperative imaging is essential to accurately determine the tumor\u0026rsquo;s location, its relationship to nearby neural and vascular tissues, and to optimize surgical planning for safe and effective removal.\u003c/p\u003e\u003cp\u003eThe diagnostic evaluation for abnormal uterine bleeding revealed a large 15\u0026times;12 cm presacral schwannoma which was discovered incidentally. The tumor followed the common schwannoma pattern by staying without any neurological effects during its development. The MRI scans helped doctors identify the tumor and create surgical plans and they used the images to determine the Klimo type III classification according to Maghrebi et al. [11].\u003c/p\u003e\u003cp\u003eThe surgical team used a combined approach between gynecological and neurosurgical experts to remove the tumor through an open abdominal procedure because of its large size and deep location. The surgical team used intraoperative neuromonitoring to track neural activity throughout the procedure which led to successful tumor extraction without nerve damage and validated the monitoring system's effectiveness for sacral nerve plexus surgeries [12].\u003c/p\u003e\u003cp\u003eThe medical community continues to discuss the need for radiation therapy in benign schwannoma cases but most experts agree that it should only be used when pathological results show malignant or atypical tissue. The patient received no additional oncological treatment because the surgical team removed the tumor completely and pathological tests showed no signs of atypical cells or tissue death. The patient stayed free of symptoms during the 34-month monitoring period while MRI scans showed no signs of tumor persistence or recurrence which supports previous research showing that complete tumor removal leads to excellent prognosis with low recurrence rates [13].\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eComplete surgical excision with careful multidisciplinary planning and intraoperative neuromonitoring ensures excellent outcomes in presacral schwannomas. This case contributes to the limited literature on pelvic schwannomas in women and underscores the value of collaborative surgical management.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003ePatient Perspective\u003c/p\u003e\n\u003cp\u003eThe patient expressed satisfaction with the outcome, reporting complete relief of symptoms and gratitude for the multidisciplinary approach to her care.\u003c/p\u003e\n\u003cp\u003eConsent for Publication\u003c/p\u003e\n\u003cp\u003eWritten informed consent for treatment and publication of this case and accompanying images was obtained from the patient.\u003c/p\u003e\n\u003cp\u003eCompeting Interests\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003eFunding\u003c/p\u003e\n\u003cp\u003eThe authors received no financial support for the research, authorship, or publication of this article.\u003c/p\u003e\n\u003cp\u003eAuthors\u0026rsquo; Contributions\u003c/p\u003e\n\u003cp\u003eConcept and design: Candost Hanedan, Neslihan \u0026Ouml;zt\u0026uuml;rk\u003cbr\u003e\u0026nbsp;Data acquisition and analysis: Candost Hanedan, Neslihan \u0026Ouml;zt\u0026uuml;rk, Berna Turhan, İnan Uzunoğlu\u003cbr\u003e\u0026nbsp;Manuscript drafting: Candost Hanedan, Neslihan \u0026Ouml;zt\u0026uuml;rk, Berna Turhan, İnan Uzunoğlu\u003cbr\u003e\u0026nbsp;Critical revision: Candost Hanedan, Neslihan \u0026Ouml;zt\u0026uuml;rk\u003cbr\u003e\u0026nbsp;Supervision: Candost Hanedan\u003cbr\u003e All authors read and approved the final manuscript.\u003c/p\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":"Presacral schwannoma, Pelvic mass, Retrorectal tumor, Schwann cell tumor, Multidisciplinary surgery, Intraoperative neuromonitoring","lastPublishedDoi":"10.21203/rs.3.rs-8007200/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8007200/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eBackground:Presacral schwannomas are extremely rare benign tumors arising from Schwann cells of peripheral nerves. Their deep pelvic location poses significant diagnostic and surgical challenges due to proximity to critical neurovascular structures.\u003c/p\u003e\n\u003cp\u003eCase presentation:We present a case of a 57-year-old postmenopausal woman with a large presacral schwannoma successfully managed through complete surgical excision using a multidisciplinary approach. During the preoperative evaluation, MRI suggested possible local invasion, leading to a joint operation with the neurosurgery team. This collaboration enabled safe dissection and complete tumor removal while minimizing neurological risks.\u003c/p\u003e\n\u003cp\u003eConclusion: This case underscores the importance of detailed preoperative imaging, intraoperative neuromonitoring, and multidisciplinary collaboration for achieving optimal outcomes in the management of presacral schwannomas.\u003c/p\u003e","manuscriptTitle":"A Rare Cause of Pelvic Mass: Presacral Giant Schwannoma – A Case Report","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-11-24 10:19:21","doi":"10.21203/rs.3.rs-8007200/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":"9b4dc985-f8e7-4098-a2b6-c69401fb1e4c","owner":[],"postedDate":"November 24th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-12-26T10:54:12+00:00","versionOfRecord":[],"versionCreatedAt":"2025-11-24 10:19:21","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8007200","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8007200","identity":"rs-8007200","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}