甲状腺结节的评估与管理-English

EvaluationandManagementofThyroidNodulesPrevalence⚫TheFraminghamstudyinUS:6.4%offemalesand1.6%ofmaleshadoneormorethyroidnodules,anannualincidenceof1.4%overthefollowing15years.⚫TheWhickhamsurveyinEngland:palpablegoitres---8.6%;palpableandvisiblegoitres---6.9%;females:males=4:1;Follow-upfor20years,amongstwomen,70%hadnogoitre,20%hadagoitreatfirstsurveybutnotatfollow-up,6%hadgoitresatbothsurveysand4%developedgoitres;⚫Postmortemstudieshaveshownthatupto50%ofthepopulationhaveeithersingleormultiplenodulesinthethyroid,manyofwhichareverysmall;⚫Highresolutionultrasoundscansrevealeddiscretenodulesinupto50%ofthosebeyondthefifthdecadeoflife;⚫Nodularthyroiddiseaseisfoundin5%ofthepopulationatpalpationscreeningandisten-foldmorefrequentatechographicscreening.⚫Thyroidnodulesarerareinchildrenandadolescentsandincreaselinearlywithage;females/malesare2~4;⚫Nodularthyroiddiseaseisaheterogeneousdisorder:nodulesmaybesingleormultiple,hyper-orhypo-functioning,benignormalignant.⚫Thyroidcancerisrare:lessthan0.5%ofallnewmalignancies;lessthan0.5%ofallcancerdeaths;⚫Thyroidcanceris6~14%ofsinglethyroidnodulesselectedforsurgery.⚫Postmortemstudies:Occultcancerinupto5%ofthyroidglandsnormaltopalpation;Mostaresmall,onlyseveralmillimetresindiameter,withoutclinicalsignificance.⚫Thyroidcancercanbeamortaldisease:welldifferentiatedtumors---mortality10%;poorlydifferentiatedandmedullary---50%;anaplastictumors---100%.⚫Malignantnodulesaccountfor5%ofallnodules.well-differentiatedcarcinomasin75%;poorlydifferentiatedoranaplasticin15%;medullarycancerin10%cases.Aetiologicalfactors⚫TSH⚫Growthstimulatingimmunoglobulins⚫Iodinedeficiency⚫ExposuretoionizingradiationDifferentialdiagnosisofthethyroidnodule⚫Colloid(adenomatoid)nodule⚫ThyroidadenomaFollicularadenomaHurthlecell⚫ThyroidcancerPrimary---Papillary,Follicular,Medullary,AnaplasticMeetastatic/directinvasionRenalcell,Breast,Lung,Melanoma,Coloncancer,Gastriccarcinoma,Pancreaticcarcinoma,Headandnecktumors,Hodgkin’sdisease;Thyroidlymphoma⚫Thyroidcyst---pure,complex⚫Thyroiditis---Acute,Subacute,Hashimoto’s;⚫Riedel’sdisease⚫Graves’disease⚫Infectious---Abscess,Tuberculosis;⚫Infiltrative/granulomatousdiseaseSarcoidosis,Amyloidosis⚫DevelopmentalabnormalitiesThyroidhemiagenesisThyroglossalductcystTeratoma⚫NeckstructuressimulatingthyroidnodulesAberrantsubclavianarteryandveinLipomasExtrathyroidalhematomaEsophagealdiverticulumParathyroidadenoma,cyst,orcarcinomaClassificationofthyroidneoplasms⚫PrimaryepithelialtumorsTumoroffollicularcellsBenign:follicularadenomaMalignant:carcinomaDifferentiated---papillary,folllicularPoorlydifferentiated---insular,othersUndifferentiated(anaplastic)ClassificationofthyroidneoplasmsTumorofCcells---MedullarycarcinomaTumoroffollicularandCcellsMixedmedullary-follicularcarcinoma⚫PrimarynonepithelialtumorsMalignantlymphomasSarcomasOthers⚫SecondarytumorsSubtypesoffollicularadenoma⚫ConventionalTrabecular/solid(embryonal)adenomaMicrofollicular(fetal)adenomaNormofollicular(simple)adenomaMacrofollicular(colloid)adenoma⚫VariantsHyalinizingtrabecularadenomaOncocytic(oxyphilicorHurthlecell)tumorAdenomaswithpapillaryhyperplasiaHyperfunctioning(toxic)adenomaAtypical(hypercellular)adenomaHistory⚫Priorexposuretoradiation⚫age:childhood,>65years---undifferentiatedthyroidcancer⚫Sex:cancer---malesratherthanfemales⚫familyhistory:multipleendocrineneoplasiasyndrometypeIIfamilialmedullarythyroidcancerHistoricalfeatureforbenigndisease⚫AfamilyhistoryofHT,benignthyroidnodule,orgoiter;⚫Symptomsofhypothyroidismorhyperthyroidism;⚫Painortendernessassociatedwiththenodule.Historicalfeatureformaligancy⚫Young(<20yearsold)orold(>70yearsold)patientage;⚫Malesex;⚫Historyofexternalneckradiationduringchildhoodoradolescence;⚫Previoushistoryofthyroidcancer;⚫Recentchangesinspeaking,breathing,orswallowing;⚫Afamilyhistoryofthyroidcancerortype2MEN.Symptomsandsigns⚫dysphagia,dyspnoeaorhoarseness⚫firmness,fixationtoadjacentstructures,vocalcordparalysisandcervicallymphadenopathy⚫multinodulargoitreandsolitarythyroidnodules⚫Thesensitivityandspecificityratesfordetectingthyroidmalignancybyhistoryandphysicalexaminationwerearound60%and80%,respectively.laboratoryevaluation⚫ThyroidhormonesandTSH⚫TPO-Ab,TgAb,TRAb⚫Thyroglobulinitsroleinthelong-termfollowupofpatientstreatedfordifferentiatedthyroidcancerisclear;⚫CalcitoninSerumTgconcentrationsreflectthreefactors⚫Themassofdifferentiatedthyriodtissurepresent⚫Anyphysicaldamageto,orinflammationof,thethyroidgland⚫Thelevelofthyroid-stimulatinghormone(TSH)-receptorstimulationAssessmentofthyroidnodule⚫PlainX-rayexaminationofthetrachea⚫CTscanningandMRI⚫Assessmentofarespiratoryflowvolumeloop⚫RadionuclideimagingTechnetium-99m(99mTc)pertechnetateIodine-123⚫Ultrasoundscanning⚫FineneedleaspirationcytologyRadionuclideimaging⚫Coldnodules:cancerouslesionslessthan20%;80%beingduetocolloidnodules,haemorrhage,cystsorinflammatorylesionssuchasHT;⚫Hotnodulesareassociatedwithalowincidenceofmalignancy;⚫Warmlesionmaybeambiguoussinceahypofunctioningmalignantnodulemaybeobscuredbyoverlyingnormaltissue.⚫Thisapproachdoesnotspecificallydistinguishbenignfrommalignantlesions.Ultrasonography⚫Itisofvalueindistinguishingsolidfromcysticlesionsofthethyroid⚫Classifynodulesassolid,mixedcysticandsolidorcysticwithgreaterthan90%accuracy⚫Malignantnodulesarehypoechoiccomparedwiththeremainderofthegland,whilebenignlesionsarehyperechoicwithasonolucentrim("halosign").⚫Therearenosonographiccriteriawhichareabletodefinebenignormalignantdisease.Thyroidhormonesuppression⚫Attemptstodistinguishbenignfrommalignantnodulesbyseekingachangeinsizeinresponsetothyroxine,perhapsrelatedtodependencyonTSHforgrowth.⚫Somecarcinomasmayrespondtosuppressionbyreducinginsize.⚫Theincidenceofcancerinnon-respondersbeingbetween12and40%.Fineneedleaspirationcytology⚫firstdescribedin1948andpioneeredbyScandinavian;⚫nowgainedwideacceptanceasthemostaccuratediagnosticprocedurefordistinguishingbenignfrommalignantthyroidnodules⚫itgiveslimitedinformationinapproximately25%ofcasesbecauseofinsufficientcellularyieldorindeterminatediagnoses.Fineneedleaspirationcytology⚫Thisinpartisduetodifficultyindistinguishingbenignadenomasfrommalignantfollicularneoplasms;surgicalexcisionofallsuchlesionsisthereforerequired⚫Thecytopathologistcanreportthatanadequatesmearcontainsnormalcellsonly,cellsfrombenignnon-tumorousconditionssuchaslymphocyticthyroiditis,orsuspicious(indeterminate)orfranklymalignantcells.Strategyfortreatmentofnodularthyroiddisease⚫Followup(waitandseepolicy)⚫Sclerotherapywithtetracyclineorethanol;⚫Thyroxinetherapy;⚫Radioiodinetreatment;⚫Surgery.