The image shows an atypical meningioma with small cell change, characterized by reduced cytoplasm and increased N/C ratio in these regions.AuthorsBlogBoardReviewCommentContactUsNewslettersStatisticsTestimonialsCDmarkersisnowpartoftheStainschapter;newMolecularmarkerschapterJobsFellowshipsConferences/WebinarsBooksCMECasesAdvertiseGrantsMedicalNewsLibrariesRocheCompanionDiagnosticLibraryRocheNTRKIHCDiagnosticLibraryCOVID-19LibraryPandemicreliefmusicawardHome>CNStumor>AtypicalmeningiomaCNStumorMeningealtumorsAtypicalmeningiomaAuthors: Chunyu"Hunter"Cai,M.D.,Ph.D.,JesseL.Kresak,M.D.,AnthonyT.Yachnis,M.D.Resident/FellowAdvisoryBoard: MeaghanMorris,M.D.,Ph.D.EditorialBoardMember: MariaMartinez-LageAlvarez,M.D.TopicCompleted:29March2021Minorchanges:29March2021Copyright:2002-2021,PathologyOutlines.com,Inc.PubMedSearch:Atypicalmeningioma[TI]freefulltext[sb]Pageviewsin2020:13,047Pageviewsin2021todate:6,577TableofContentsDefinition/general|Essentialfeatures|ICDcoding|Epidemiology|Sites|Pathophysiology|Etiology|Clinicalfeatures|Diagnosis|Radiologydescription|Prognosticfactors|Casereports|Treatment|Grossdescription|Frozensectiondescription|Microscopic(histologic)description|Microscopic(histologic)images|Cytologydescription|Positivestains|Negativestains|Molecular/cytogeneticsdescription|Samplepathologyreport|Differentialdiagnosis|Boardreviewstylequestion#1|Boardreviewstyleanswer#1Citethispage:CaiC,KresakJ,YachnisA.Atypicalmeningioma.PathologyOutlines.comwebsite.https://www.pathologyoutlines.com/topic/cnstumoratypicalmeningioma.html.AccessedJune3rd,2021.Definition/generalAmeningiomaofintermediateaggressivenessbetweenbenignandmalignantforms,comprising5-15%ofmeningiomasWHOgradeIIDiagnosticcriteria:fulfillingeither1of2majorcriteriaor3of5minorcriteriaMajorcriteria:4-19mitoticfigures/10highpowerfieldsBraininvasionMinorcriteria:IncreasedcellularitySmallcellswithhighN/CratioLargeandprominentnucleoliPatternlessorsheet-likegrowth(lossoflobulararchitecture)Fociofspontaneousorgeographicnecros

Atypical meningioma refers to a more aggressive form of meningioma and denotes a WHO grade II tumor (along with two histological variants, clear cell ...×ArticlesLogInCasesSignUpCoursesQuizBlogDonateAbout×MenuSearchADVERTISEMENT:Radiopaediaisfreethankstooursupportersandadvertisers.BecomeaGoldSupporterandseenoads.ArticlesCasesCoursesLogInLoginSignup{"url":"/signup-modal-props.json?lang=us\u0026email="}ArticlesCasesCoursesQuizAboutBlogGoad-freeSearchAtypicalmeningiomaDrMostafaEl-Feky◉andAssocProfFrankGaillard◉◈etal.AtypicalmeningiomareferstoamoreaggressiveformofmeningiomaanddenotesaWHOgradeIItumor(alongwithtwohistologicalvariants, clearcellmeningioma andchordoidmeningioma).Atypicalmeningiomasaccountfor20-30%ofallmeningiomas1,3. Itshouldbenotedthatepidemiology,clinicalpresentation,andradiographicfeaturesdonotreliablydistinguishgradeI(benign) fromgradeII(atypical)meningiomas,andthustheyarenotunnecessarilyrepeatedhere.Generally,thesetumorsgrowfaster,havemoreheterogeneous/aggressiveimagingappearances,andhaveatendencytorecurearly. Onthispage:Article:TerminologyPathologyRadiographicfeaturesTreatmentandprognosisRelatedarticlesReferencesImages:CasesandfiguresTerminologyTheuseoftheword"atypical" todenoteahighergrade,referstothehistologicalappearances(seebelow).However,itisperhapsunfavorableasitcausesconfusionformanyotherclinicianswhoareusedtoreferringtosomethingbeing'atypical'toindicatethatitdoesn'tlooklikethe'usual'garden-varietytumor/condition.Oneshouldthereforenotconfuse"atypicalmeningioma"withhistologicalvariants,manyofwhichhaveunusualimagingandhistologicalfeaturesbutarenonethelessWHOgradeItumors(seemeningiomaarticleforfurtherdiscussionofhistologicalvariants). PathologyAtypical(WHOgradeII)meningiomasarecharacterizedhistologicallyby1: 4to19mitosespertenhigh-powerfields3ormoreofthefollowing5histologicfeatures:necrosissheet-likegrowthsmallcellchangeincreasedcellularityprominentnucleolidirectinvasionofbrainparenchymaItisimportanttonotewhenreadingolderliterature,thatitisonlysin

Atypical meningiomas are uncommon and have poorer prognosis when compared to benign meningiomas. Atypical meningiomas have a recurrence rate of 28%.SkiptomaincontentAtypicalMeningioma,WHOGradeII,InvasiveBackground—General:Meningiomasarethemostcommonextra-axialneoplasmsandaccountfor15%ofallintracranialtumors.ThreegradesexistbasedontheWHOcriteria.MostareWHOGradeI;approximately6%areWHOGradeII;andrareareWHOGradeIIIneoplasms(malignantwithmetastaticpotential).Manyvariantsofmeningiomahavebeendescribedintheliterature.AtypicalmeningiomasfallunderWHOGradeIItumors,accountingfor5–15%ofallmeningiomas.TheincidenceofreportingofthesetumorshasincreasedsincerevisiontotheWHOclassificationin2007.Background—Pediatric/InfantileMeningioma:Pediatricmeningiomasarerareandaccountforfewerthan5%ofallpediatricintracranialneoplasms.Infantilemeningiomas(<12monthsold)areevenrarer,withfewerthan30reportedcases.Pediatricpatientsusuallypresentwithincreasedintracranialpressureandseizures.Intraventricularandskullbaselocationsaremorecommoninchildrenrelativetoadults.RiskfactorsforpediatricmeningiomasincludeneurofibromatosisIIandpriorradiationtherapy.Thereisahigherincidenceofatypicaloraggressivesubtypesinpediatricpatients.KeyDiagnosticImagingFeatures:BrainCTshowsanintra-axialorextra-axialmasswithbonedestruction.Thetumorisusuallyhyperdensewithperitumoraledemabutminimalornocalcification.BrainMRIshowsindistincttumormarginswithinfiltratingtumorinterdigitatingwithnormalbrainparenchymaonT1weightedimaging.T2WIandFLAIRimagesshowperitumoraledema.Postcontrastimagingtypicallyshowsanenhancingtumorthatinvolvesboththeskullandscalp.MRVmayshowduralsinusinvasion.Conventionalangiographyshowsanintensevascularstainthatappearsearlyandpersistslate.Thevenousphasemayshowduralsinusinvasion.Typicalimagingfindingsofmeningiomadonotexcludeatypicalvariants.Histologyisneededfordefinitivediagnosis.Histology:4–19mitoticfigures/10HPFORBrainInvasionORThreeofthefollowinghistologicfeatures:IncreasedcellularitySmallcellsthathavehighnucleartocyt

Long-term survival is possible for patients with atypical meningiomas treated with surgery and postoperative RT. Multivariate analysis confirmed that age (<50 ...Clipboard,SearchHistory,andseveralotheradvancedfeaturesaretemporarilyunavailable.SkiptomainpagecontentCOVID-19InformationPublichealthinformation(CDC)Researchinformation(NIH)SARS-CoV-2data(NCBI)Preventionandtreatmentinformation(HHS)Español AccesskeysNCBIHomepageMyNCBIHomepageMainContentMainNavigationSearch:SearchAdvancedClipboardUserGuideSaveEmailSendtoClipboardMyBibliographyCollectionsCitationmanagerDisplayoptionsDisplayoptionsFormatAbstractPubMedPMIDSavecitationtofileFormat:Summary(text)PubMedPMIDAbstract(text)CSVCreatefileCancelEmailcitationSubject:1selecteditem:23871812-PubMedTo:Format:SummarySummary(text)AbstractAbstract(text)MeSHandotherdataSendemailCancelAddtoCollectionsCreateanewcollectionAddtoanexistingcollectionNameyourcollection:Namemustbelessthan100charactersChooseacollection:UnabletoloadyourcollectionduetoanerrorPleasetryagainAddCancelAddtoMyBibliographyMyBibliographyUnabletoloadyourdelegatesduetoanerrorPleasetryagainAddCancelYoursavedsearchNameofsavedsearch:Searchterms:TestsearchtermsWouldyoulikeemailupdatesofnewsearchresults?SavedSearchAlertRadioButtonsYesNoEmail:(change)Frequency:MonthlyWeeklyDailyWhichday?ThefirstSundayThefirstMondayThefirstTuesdayThefirstWednesdayThefirstThursdayThefirstFridayThefirstSaturdayThefirstdayThefirstweekdayWhichday?SundayMondayTuesdayWednesdayThursdayFridaySaturdayReportformat:SummarySummary(text)AbstractAbstract(text)PubMedSendatmost:1item5items10items20items50items100items200itemsSendevenwhentherearen'tanynewresultsOptionaltextinemail:SaveCancelCreateafileforexternalcitationmanagementsoftwareCreatefileCancelYourRSSFeedNameofRSSFeed:Numberofitemsdisplayed:510152050100CreateRSSCancelRSSLinkCopyFulltextlinksElsevierScienceFulltextlinksActionsCiteFavoritesDisplayoptionsDisplayoptionsFormatAbstractPubMedPMIDSharePermalinkCopyPagenavigationTitle&authorsAbstractCommen

Meningiomas account for approximately one-third of primary central nervous system tumors (and). Most meningiomas are benign (World Health ...

Atypical meningioma is rare tumor and there is no accurate guide line for optimal treatment. This retrospective study analyzed the prognostic ...NCBISkiptomaincontentSkiptonavigationResourcesHowToAboutNCBIAccesskeysMyNCBISignintoNCBISignOutJournalListJKoreanNeurosurgSocv.60(6);2017NovPMC5678060JKoreanNeurosurgSoc.2017Nov;60(6):661–666.Publishedonline2017Oct25.doi: 10.3340/jkns.2017.0303.008PMCID:PMC5678060PMID:29142625PrognosticFactorsofAtypicalMeningioma:OverallSurvivalRateandProgressionFreeSurvivalRateJaeHoLee,M.D.,1OhLyongKim,M.D.,1YoungBeomSeo,M.D.,1andJunHyukChoi,M.D.2JaeHoLee1DepartmentsofNeurosurgery,YeungnamUniversityMedicalCenter,YeungnamUniversityCollegeofMedicine,Daegu,KoreaFindarticlesbyJaeHoLeeOhLyongKim1DepartmentsofNeurosurgery,YeungnamUniversityMedicalCenter,YeungnamUniversityCollegeofMedicine,Daegu,KoreaFindarticlesbyOhLyongKimYoungBeomSeo1DepartmentsofNeurosurgery,YeungnamUniversityMedicalCenter,YeungnamUniversityCollegeofMedicine,Daegu,KoreaFindarticlesbyYoungBeomSeoJunHyukChoi2Pathology,YeungnamUniversityMedicalCenter,YeungnamUniversityCollegeofMedicine,Daegu,KoreaFindarticlesbyJunHyukChoiAuthorinformationArticlenotesCopyrightandLicenseinformationDisclaimer1DepartmentsofNeurosurgery,YeungnamUniversityMedicalCenter,YeungnamUniversityCollegeofMedicine,Daegu,Korea2Pathology,YeungnamUniversityMedicalCenter,YeungnamUniversityCollegeofMedicine,Daegu,KoreaAddressforreprints:JaeHoLee,M.D.,DepartmentofNeurosurgery,YeungnamUniversityMedicalCenter,YeungnamUniversityCollegeofMedicine,170Hyeonchung-ro,Nam-gu,Daegu42415,Korea,Tel:+82-53-620-3790,3792,Fax:+82-53-620-3770,E-mail:moc.revan@2339imisasReceived2017Mar31;Revised2017Jun29;Accepted2017Jul3.Copyright©2017TheKoreanNeurosurgicalSocietyThisisanOpenAccessarticledistributedunderthetermsoftheCreativeCommonsAttributionNon-CommercialLicense(http://creativecommons.org/licenses/by-nc/4.0)whichpermitsunrestrictednon-commercialuse,distribution,andreproductioninanymedium,providedtheoriginalworkisproperlycited.Thisar