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1、胃肠道间质瘤概念胃肠道间质瘤（GastrointestinalStromalTumors,GIST）是一类起源于胃肠道间叶组织的肿瘤，占消化道间叶肿瘤的大部分。Mazur等于1983年首次提出了胃肠道间质肿瘤这个概念。发病率及发病部位Gastrointestinalstromaltumours(GISTs)represent0.1-3%ofgastrointestinalmalignanciesand80%ofgastrointestinalmesenchymaltumoursTheprevalenceof
2、thediseaseisestimatedat11to20casespermillionofpopulation[1、2、3].SixtypercentofGISTspresentinthestomach,30%inthesmallintestine,5%inthecolonandrectumand5%intheoesophagusAbout140newcasesarerecognizedinGreeceeveryyear;themeanageofdiagnosisis60yearsandthemaleto
3、femaleratioapproximately1.4:1[4].GIST的症状、体征Thedelayeddiagnosisofstromaltumours,duetothelackofspecificsymptoms,resultsin25%ofpatientspresentingwithmetastaticdisease.Itoftentakesupto6monthsfromtheonsetofinitialsymptomstoreachadiagnosis[5].Themostfrequentmani
4、festationsofthediseaseincludegastrointestinalhaemorrhage,fatigueduetochronicanaemia,lossofappetite,weightloss,vom-iting,thepresenceofapalpablemass,andnon-spe-cificabdominalpain.Thesesymptomsappearduetodisplacement,ratherthaninfiltrationofnearbystructures.A
5、combinationofsymptomsispresentinover5%ofpatients[6、7]病理诊断基因诊断Thekitproteinisexpressedin90-95%ofGISTs.Thisproteinrepresentsatransmembranereceptorthatactslikeatyrosinekinase.In5-10%ofGISTs,mutationsinPlatelet-DerivedGrowthFactorRecep-tor(PDGFRαandPDHFRβ)arep
6、resentthataremutuallyexclusivetotheKITmutations,whilesomeGISTshavenodetectablemutationsineitherreceptor(wild-typeGISTs)[8,9].TheexpressionofCD34ismorefrequentingastricGISTs(85%),whileitispositiveinonly50%ofGISTsthatarisefromthesmallintestine[10].CD34isuniv
7、ersallyexpressedinoesophagealGISTs.Anotherrecentlyrecognizedmarkeriscyclooxygenase2(COX-2)Atleast80%ofGISTsexpressthisprotein[11]病理图示Themajorityofstromaltumours(70%)consistofspindlecells,20%aremadeupofepithelioidcellsandtherestpresentwithmixedmorphologyCTa
8、ndEUSComputedtomography(CT)andendoscopicultrasound(EUS)havecontributedsignificantlytothediagnosisofGISTs.Computedtomographyrepre-sentsthebestimagingmodalityfortumours>5cm,whileEUSismostusefulinidentifyingtumo
