{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,5]],"date-time":"2026-08-05T00:48:55Z","timestamp":1785890935953,"version":"3.56.0"},"reference-count":22,"publisher":"Journal of Neurosurgery Publishing Group (JNSPG)","issue":"5","license":[{"start":{"date-parts":[[2026,8,3]],"date-time":"2026-08-03T00:00:00Z","timestamp":1785715200000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J Neurosurg Case Lessons"],"published-print":{"date-parts":[[2026,8,3]]},"abstract":"<jats:sec>\n                    <jats:title>BACKGROUND<\/jats:title>\n                    <jats:p>Vestibular schwannomas (VSs) are common benign tumors of the cerebellopontine angle, often treated with surgery or stereotactic radiosurgery to preserve nerve function. Malignant transformation of VS (MTVS) is exceedingly rare and has been primarily associated with neurofibromatosis type 1 (NF1), neurofibromatosis type 2\u2013related schwannomatosis (NF2-SWN), or prior radiation exposure. However, cases of MTVS occurring without these risk factors are rare and remain poorly understood.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>OBSERVATIONS<\/jats:title>\n                    <jats:p>A 58-year-old woman without neurofibromatosis underwent subtotal VS resection in 2019, with stable residual tumor and no adjuvant treatment. In 2023, she developed acute neurological decline, and imaging suggested malignant transformation or a new tumor. Surgery confirmed a high-grade neoplasm, likely leiomyosarcoma or malignant peripheral nerve sheath tumor, with genetic analysis revealing no NF1 or NF2-SWN mutations. She received adjuvant stereotactic radiation therapy, and at the 3-month follow-up, imaging showed stable residual disease. However, she continued to experience persistent neurological deficits, including facial weakness, ataxia, and intention tremor, with a Karnofsky Performance Scale score of 60%.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>LESSONS<\/jats:title>\n                    <jats:p>MTVS is extremely rare without neurofibromatosis or prior radiation therapy, potentially driven by surgical inflammation or unidentified genetic alterations. While increased surveillance after subtotal resection may be considered, more research is needed to identify predictive markers and guide clinical management.<\/jats:p>\n                    <jats:p>\n                      <jats:ext-link xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" ext-link-type=\"uri\" xlink:href=\"https:\/\/thejns.org\/doi\/10.3171\/CASE251003\">https:\/\/thejns.org\/doi\/10.3171\/CASE251003<\/jats:ext-link>\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.3171\/case251003","type":"journal-article","created":{"date-parts":[[2026,8,5]],"date-time":"2026-08-05T00:01:42Z","timestamp":1785888102000},"source":"Crossref","is-referenced-by-count":0,"title":["Sporadic sarcoma arising from a previously resected benign vestibular schwannoma without neurofibromatosis or radiosurgery: illustrative case"],"prefix":"10.3171","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8226-1022","authenticated-orcid":true,"given":"Simon A.","family":"Menaker","sequence":"first","affiliation":[{"name":"Departments of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michelot","family":"Michel","sequence":"additional","affiliation":[{"name":"Departments of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania"},{"name":"Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Catherine M.","family":"Garcia","sequence":"additional","affiliation":[{"name":"Departments of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Edward","family":"Robinson","sequence":"additional","affiliation":[{"name":"Departments of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xuemo","family":"Fan","sequence":"additional","affiliation":[{"name":"Pathology and Laboratory Medicine, Cedars-Sinai Medical Center, Los Angeles, California"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gregory P.","family":"Lekovic","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, University of California, Los Angeles, California"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"John S.","family":"Yu","sequence":"additional","affiliation":[{"name":"Departments of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1754","reference":[{"issue":"12","key":"bib1","series-title":"Ann Med Surg (Lond)","first-page":"6206","article-title":"Is vestibular schwannoma really a benign tumor? 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Neurosurg Rev. 2022;45(1):915-922. doi:10.1007\/s10143-021-01620-3"},{"issue":"11","key":"bib3","series-title":"Acta Neurochir (Wien)","first-page":"2595","article-title":"Surgical management for large vestibular schwannomas: a systematic review, \u00admeta-analysis, and consensus statement on behalf of the EANS skull base section","volume":"162","author":"Starnoni","year":"2020","unstructured":"Starnoni DGiammattei LCossu GSurgical management for large vestibular schwannomas: a systematic review, \u00admeta-analysis, and consensus statement on behalf of the EANS skull base section. Acta Neurochir (Wien). 2020;162(11):2595-2617. doi:10.1007\/s00701-020-04491-7"},{"key":"bib4","series-title":"World Neurosurg","first-page":"99","article-title":"High-grade sarcoma arising within a previously irradiated vestibular schwannoma: a case report and literature review","volume":"144","author":"Boucher","year":"2020","unstructured":"Boucher ABMendoza PNeill SGEaton BOlson JJ.High-grade sarcoma arising within a previously irradiated vestibular schwannoma: a case report and literature review. World Neurosurg. 2020;144:99-105. doi:10.1016\/j.wneu.2020.08.170"},{"issue":"3","key":"bib5","series-title":"Skull Base","first-page":"179","article-title":"A case of high-grade undifferentiated sarcoma after surgical resection and stereotactic radiosurgery of a vestibular schwannoma","volume":"20","author":"Yang","year":"2010","unstructured":"Yang TRockhill JBorn DESekhar LN.A case of high-grade undifferentiated sarcoma after surgical resection and stereotactic radiosurgery of a vestibular schwannoma. Skull Base. 2010;20(3):179-183. doi:10.1055\/s-0029-1242195"},{"issue":"6","key":"bib6","series-title":"J Korean Med Sci","first-page":"817","article-title":"Vestibular schwannoma with malignant transformation: a case report","volume":"16","author":"Son","year":"2001","unstructured":"Son EIKim IMKim SP.Vestibular schwannoma with malignant transformation: a case report. J Korean Med Sci. 2001;16(6):817-821. doi:10.3346\/jkms.2001.16.6.817"},{"issue":"6","key":"bib7","series-title":"J Neurosurg","first-page":"946","article-title":"Recurrence of acoustic neurilemoma as a malignant spindle-cell neoplasm. Case report","volume":"73","author":"McLean","year":"1990","unstructured":"McLean CALaidlaw JDBrownbill DSGonzales MF.Recurrence of acoustic neurilemoma as a malignant spindle-cell neoplasm. Case report. J Neurosurg. 1990;73(6):946-950. doi:10.3171\/jns.1990.73.6.0946"},{"issue":"3","key":"bib8","series-title":"Am J Surg Pathol","first-page":"325","article-title":"Malignant peripheral nerve sheath tumors of cranial nerves and intracranial contents: a clinicopathologic study of 17 cases","volume":"33","author":"Scheithauer","year":"2009","unstructured":"Scheithauer BWErdogan SRodriguez FJMalignant peripheral nerve sheath tumors of cranial nerves and intracranial contents: a clinicopathologic study of 17 cases. 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Otol Neurotol. 2015;36(8):1301-1308. doi:10.1097\/MAO.0000000000000801"},{"issue":"5","key":"bib10","series-title":"Neurosurgery","first-page":"934","article-title":"Stereotactic radiosurgery for vestibular schwannoma in neurofibromatosis type 2: an international multicenter case series of response and malignant transformation risk","volume":"92","author":"Bin-Alamer","year":"2023","unstructured":"Bin-Alamer OFaramand AAlarifi NAStereotactic radiosurgery for vestibular schwannoma in neurofibromatosis type 2: an international multicenter case series of response and malignant transformation risk. Neurosurgery. 2023;92(5):934-944. doi:10.1227\/neu.0000000000002436"},{"key":"bib11","series-title":"Radiat Oncol","article-title":"Factors of influence upon overall survival in the treatment of intracranial MPNSTs. Review of the literature and report of a case","volume":"5","author":"Gousias","year":"2010","unstructured":"Gousias KBostr\u00f6m JKovacs ANiehusmann PWagner IKristof R.Factors of influence upon overall survival in the treatment of intracranial MPNSTs. Review of the literature and report of a case. Radiat Oncol. 2010;5:114. doi:10.1186\/1748-717X-5-114"},{"issue":"5","key":"bib12","series-title":"Cancer","first-page":"1065","article-title":"Malignant peripheral nerve sheath tumors: prognostic factors and survival in a series of patients treated at a single institution","volume":"107","author":"Anghileri","year":"2006","unstructured":"Anghileri MMiceli RFiore MMalignant peripheral nerve sheath tumors: prognostic factors and survival in a series of patients treated at a single institution. Cancer. 2006;107(5):1065-1074. doi:10.1002\/cncr.22098"},{"key":"bib13","series-title":"Front Oncol","article-title":"Malignant transformation in vestibular schwannoma: clinical study with survival analysis","volume":"11","author":"Li","year":"2021","unstructured":"Li JWang QZhang MZhang GZhang SHui X.Malignant transformation in vestibular schwannoma: clinical study with survival analysis. Front Oncol. 2021;11:655260. doi:10.3389\/fonc.2021.655260"},{"issue":"4","key":"bib14","series-title":"Neurosurgery","first-page":"684","article-title":"Management of 1000 vestibular schwannomas (acoustic neuromas): the facial nerve\u2014preservation and restitution of function","volume":"40","author":"Samii","year":"1997","unstructured":"Samii MMatthies C.Management of 1000 vestibular schwannomas (acoustic neuromas): the facial nerve\u2014preservation and restitution of function. Neurosurgery. 1997;40(4):684-695. doi:10.1097\/00006123-199704000-00006"},{"issue":"6","key":"bib15","series-title":"Ann Surg","first-page":"1014","article-title":"Clinical, pathological, and molecular variables predictive of malignant peripheral nerve sheath tumor outcome","volume":"249","author":"Zou","year":"2009","unstructured":"Zou CSmith KDLiu JClinical, pathological, and molecular variables predictive of malignant peripheral nerve sheath tumor outcome. Ann Surg. 2009;249(6):1014-1022. doi:10.1097\/SLA.0b013e3181a77e9a"},{"issue":"2","key":"bib16","series-title":"Oncologist","first-page":"193","article-title":"Malignant peripheral nerve sheath tumors","volume":"19","author":"Farid","year":"2014","unstructured":"Farid MDemicco EGGarcia RMalignant peripheral nerve sheath tumors. Oncologist. 2014;19(2):193-201. doi:10.1634\/theoncologist.2013-0328"},{"issue":"5","key":"bib17","series-title":"Mol Cancer Ther","first-page":"1157","article-title":"Dual targeting of AKT and mammalian target of rapamycin: a potential therapeutic approach for malignant peripheral nerve sheath tumor","volume":"8","author":"Zou","year":"2009","unstructured":"Zou CYSmith KDZhu QSDual targeting of AKT and mammalian target of rapamycin: a potential therapeutic approach for malignant peripheral nerve sheath tumor. Mol Cancer Ther. 2009;8(5):1157-1168. doi:10.1158\/1535-7163.MCT-08-1008"},{"issue":"2","key":"bib18","series-title":"J Radiosurg SBRT","first-page":"147","article-title":"Malignant peripheral nerve sheath tumor at the cerebellopontine angle treated with Gamma Knife radiosurgery: case report and review of the literature","volume":"2","author":"Raper","year":"2013","unstructured":"Raper DMSSweiss FAlmira-Suarez MIHelm GSheehan JP.Malignant peripheral nerve sheath tumor at the cerebellopontine angle treated with Gamma Knife radiosurgery: case report and review of the literature. J Radiosurg SBRT. 2013;2(2):147-153."},{"issue":"4","key":"bib19","series-title":"Clin Exp Metastasis","first-page":"319","article-title":"Potential impact of invasive surgical procedures on primary tumor growth and metastasis","volume":"35","author":"Alieva","year":"2018","unstructured":"Alieva Mvan Rheenen JBroekman MLD.Potential impact of invasive surgical procedures on primary tumor growth and metastasis. Clin Exp Metastasis. 2018;35(4):319-331. doi:10.1007\/s10585-018-9896-8"},{"issue":"4","key":"bib20","series-title":"Cancer","first-page":"805","article-title":"Myoid differentiation and prognosis in adult pleomorphic sarcomas of the extremity: an analysis of 92 cases","volume":"98","author":"Deyrup","year":"2003","unstructured":"Deyrup ATHaydon RCHuo DMyoid differentiation and prognosis in adult pleomorphic sarcomas of the extremity: an analysis of 92 cases. Cancer. 2003;98(4):805-813. doi:10.1002\/cncr.11617"},{"issue":"6","key":"bib21","series-title":"Mod Pathol","first-page":"582","article-title":"Loss of H3K27 tri-methylation is a diagnostic marker for malignant peripheral nerve sheath tumors and an indicator for an inferior survival","volume":"29","author":"Cleven","year":"2016","unstructured":"Cleven AHGSannaa GAABriaire-de Bruijn ILoss of H3K27 tri-methylation is a diagnostic marker for malignant peripheral nerve sheath tumors and an indicator for an inferior survival. 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