Isolated Cerebellar Metastasis as the Initial Presentation of Follicular Thyroid Carcinoma: A Rare Neurosurgical Encounter

Isolated Cerebellar Metastasis as the Initial Presentation of Follicular Thyroid Carcinoma: A Rare Neurosurgical Encounter | 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 Isolated Cerebellar Metastasis as the Initial Presentation of Follicular Thyroid Carcinoma: A Rare Neurosurgical Encounter Preeti Singh, Harsh Patel, Abhaya Kumar This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7892596/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 Brain metastases from follicular thyroid carcinoma (FTC) are exceptionally rare, especially in the infratentorial region. Even rarer is when such a lesion precedes the diagnosis of the primary tumor. This case highlights the importance of maintaining diagnostic vigilance for metastatic disease, even in patients with seemingly benign thyroid pathology. Case Presentation: A 55-year-old female presented with progressive imbalance and headache. MRI revealed a solid-cystic lesion in the cerebellar vermis compressing the fourth ventricle. She had a prior diagnosis of colloid goiter based on fine-needle aspiration cytology (FNAC). Intraoperatively, the lesion mimicked a hemangioblastoma; frozen section supported this diagnosis. However, final histopathology and immunohistochemistry confirmed metastatic FTC. Subsequent PET-CT and repeat thyroid FNAC confirmed the primary tumor, leading to total thyroidectomy and radioactive iodine (RAI) therapy. Conclusion This case is likely the first reported instance of isolated cerebellar metastasis from FTC, masquerading as a primary CNS tumor. Surgeons should maintain a high index of suspicion when encountering posterior fossa tumors with atypical features, even with a prior benign thyroid FNAC. Full Text Additional Declarations No competing interests reported. Patient consent has been taken to publish the study. 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-7892596","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":533768549,"identity":"041d8ffa-96d9-4eec-946f-baec59a060c3","order_by":0,"name":"Preeti 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Rare Neurosurgical Encounter","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"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":"","lastPublishedDoi":"10.21203/rs.3.rs-7892596/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7892596/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e\u003cp\u003eBrain metastases from follicular thyroid carcinoma (FTC) are exceptionally rare, especially in the infratentorial region. Even rarer is when such a lesion precedes the diagnosis of the primary tumor. This case highlights the importance of maintaining diagnostic vigilance for metastatic disease, even in patients with seemingly benign thyroid pathology.\u003c/p\u003e\u003ch2\u003eCase Presentation:\u003c/h2\u003e\u003cp\u003eA 55-year-old female presented with progressive imbalance and headache. MRI revealed a solid-cystic lesion in the cerebellar vermis compressing the fourth ventricle. She had a prior diagnosis of colloid goiter based on fine-needle aspiration cytology (FNAC). Intraoperatively, the lesion mimicked a hemangioblastoma; frozen section supported this diagnosis. However, final histopathology and immunohistochemistry confirmed metastatic FTC. Subsequent PET-CT and repeat thyroid FNAC confirmed the primary tumor, leading to total thyroidectomy and radioactive iodine (RAI) therapy.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e\u003cp\u003eThis case is likely the first reported instance of isolated cerebellar metastasis from FTC, masquerading as a primary CNS tumor. Surgeons should maintain a high index of suspicion when encountering posterior fossa tumors with atypical features, even with a prior benign thyroid FNAC.\u003c/p\u003e","manuscriptTitle":"Isolated Cerebellar Metastasis as the Initial Presentation of Follicular Thyroid Carcinoma: A Rare Neurosurgical Encounter","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-25 21:56:48","doi":"10.21203/rs.3.rs-7892596/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":"d5ca8a68-e202-4353-953c-83a5011548a3","owner":[],"postedDate":"October 25th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-10-27T13:03:15+00:00","versionOfRecord":[],"versionCreatedAt":"2025-10-25 21:56:48","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7892596","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7892596","identity":"rs-7892596","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}