專業(yè)英語 Unit 16教案學習資料

PAGE6PAGE6UnitSixteenPATHOLOGICPROCESSESINVOLVINGTHEORALMUCOSATheoralmucousmembranereactstovariousformsofinjuriousstimulianddevelopslesionsifthestimuliornoxiousinfluencesaresufficienttoproducedisease.Lesionsoccurringontheoralmucosamaybeofseveraldistinctclinicalforms,andasimilartypeofgrosslesionmaybeproducedbyalargevarietyofentirelydifferentagents.Theappearanceofthegrosslesionisusuallyinsufficientforadequatediagnosis.Distributionofthelesions,clinicalhistory,andpasthistorymayhavesomediagnosticvalue,butmicroscopicexaminationisoftennecessaryforexactdiagnosis.Themicroscopicfeaturesofalesionmaybenonspecific,anddiagnosiscanbemadeonlybypainstakingcorrelationofgrossappearance,clinicalhistory,andmicroscopicfindings.Ingeneral,thediagnosisoforallesionsdependsuponanevaluationofbothclinicalandmicroscopicfeatures.GROSSORCLINICALLESIONSEssentially,alldiseasesoftheoralmucosaaremanifestedclinicallybytheappearanceofgrosslyvisibleormacroscopiclesions.Theselesionscompriseasurprisinglysmallnumberofbasictypesorforms:macule,papule,plaque,vesicle,bulla,pustule,ulcer,erosion,nodule,tumor,atrophicarea.Macule.Amaculeisacircumscribed,non-raisedareaofalteredcolorationvaryinginsizefromapinheadtoseveralcentimetersindiameter.Maculesareusuallydeeperincolorthanthesurroundingnormalmucosaandmaybered,red-brown,orbrown-black.Amaculareruptionorrashmayrepresentpunctatehemorrhagesorpetechiaeasseeninscurvyorthrombocytopenicpurpura,melanindepositionasinAddison'sdisease,orsmallvascularmalformationsasinhereditarytelangiectasia.Maculesmayvaryinshapefromcirculartoovoidtosomewhatlinear.Papule.Apapuleisasmall,circumscribed,solid,elevatedareavaryinginsizefromapinheadto5mm.Thebaseisroundorovoid,andthesurfaceconfigurationmaybepointed,rounded,orflattened.Apapulareruptionontheoralmucosausuallyconsistsoflargenumbersofindividualpinbeadlesionsarrangedinvaryingpatterns.Thecolorofpapulesonoralmucousmembraneisusuallygray-white,andthegrosslesioncomposedofnumbersofpapulesmaybewhite.Lichenplanus,aninflammatorydermatosis,appearsasatypicalpapulareruptionoftheoralmucosa,withpapulesarrangedinlacelike,plaquelike,orevenannularpatterns.Plaque.Aplaqueisasmallorlarge,raised,firm:clearlydemarcatedareaofgrayorwhitecoloration.Thesurfacetexturemayberelativelysmoothorroughandpebbled.Cracksorfissuresmaydividethelesion.Leukoplakia,carcinoma,anddiscoidlupuserythematosusmayappearasplaques.Multiple,closelyplacedpapulesmayresembleaplaquesuperficially,butcarefulexaminationwithamagnifyingglasswillrevealthepunctatelesions,suchaslichenplanus,ratherthanthecontinuousplaquelesion.Vesicle.Avesicleisasmall(2to5mm),circumscribed,elevatedlesioncomposedofathinsurfacecoveringoverlyingandcontaininganaccumulationoffluid.Avesiculareruptionmayconsistofasinglelesionormultiplelesionsindifferentstagesofformationandhealing.Thecoveringorvesicularmembranemaybethinanddelicateorthick,dependinguponwhetherthevesicleissubepithelialorintraepithelial.Thelattertypehasathincoveringsinceonlypartoftheepitheliumformsthevesicularmembrane.Thefluidmaybeclearorslightlyred,dependingupontheseverityoftheinflammatoryreactionatthebaseofthevesicle.Asthevesicularmembraneruptures,anulcerforms.Vesicalareruptionsmaybeseeninsuchdiverseconditionsasviralinfections,drugreactions,burns,andvesiculardermatoses.Bulla.Abullaisalarge,vesicular-typelesionranginginsizefrom5mmtoseveralcentimeters.Theoutercoveringofthebullaorblebmaybethinorrelativelythick,dependinguponthesubepithelialorintraepithelialcharacterofthelesion.Thecoveringmembraneofthebullamaybetenseorlax,dependingupontheamountoffluid.Abullouslesionmaydevelopdirectlyormayformfromtheunionofseveralvesicleseruptingclosetogether.Bullaearecharacteristicallyseeninsuchdiseasesaspemphigusandpemphigoid.Bullaemayalsoappearinsuchcharacteristicallyvesiculareruptionsaserythemamultiformeandherpeticstomatitis.Duringeruptionsusuallyinvolvebothvesiclesandbullae.Pustule.Apustuleisavesiculartypeoflesioncontainingpurulentmaterialinsteadofclearfluid.Pustulesonoralmucosaareunusualbut.appearinsuchconditionsaspyostomatitis.Ulcer.Anulcerisadefectorbreakincontinuityoftheepithelialcomponentofpunched-outareaexists.Theflooroftheulceriscomposedofconnectivetissueandfibrinwithpolymorphonuclearleukocyteinfiltration.Thelossofepitheliumresultsinanacuteinflammatorylesion.Anulcermaybesmall(2mm)orquitelarge(severalcentimeters).Theedgesofanulcermayberaggedorsharp,maybeundermined,asintuberculosis,orraisedandindurated,asinmalignanttumors.Usually,ulcersareround,butelongatedulceratedareasmayoccur,particularlyasaresponsetomechanicalorchemicaltrauma.Theflooroftheulcermayappearyellowandpurulent,reddened,orgray-white.Ulcersmayresultfromtheruptureofvesiclesorbullae.Varyingamountsoferythemamayappearattheperipheryoftheulcer.Ulcerstendtobepainful.Erosion:Anerosionisashallowdefectinmucosarepresentinglossofepitheliumdowntobutnotincludingthestratumgerminativum.Erosionsofthemucosaareusuallyproducedbymechanicaltrauma;theymayhavealinearoutlinewithindistinctmargins.Theyappearredbecause,withthelossofamajorportionofepithelium,thevascularityoftheunderlyingconnectivetissuebecomesmorevisible.Erosionsmaybepainful.Nodule.Anoduleisasolidelevatedlesionofthemucosa,varyinginsizefrom5mmto2cm.Anoduleisformedbyamassofconnectivetissueforcingtheoverlyingepitheliumoutwardtoproduceasurfacelesion.Fibromaandnevusaretypicalexamplesofnodules.Tumor.Atumorisasolidgrowthofvaryingsizethatarisesfrommucosaandprojectsoutward.Theselesionsincludetrueneoplasmswithspecifichistopathologicfeaturesandtumorlikelesionssuchasgranulomapyogenicumandangiogranuloma.Truetumorsmaybebenignormalignant.Grossfeaturesareentirelyinsufficientforthedifferentiationofbenignandmalignantlesions,andabiopsyspecimenforhistologicstudyismandatory.Certainclinicalfeaturesmaybehelpful,benigntumorstendtohaveamoreregularsurfaceandarerelativelymovableuponpalpation;malignanttumorstendtobefixedtoadjacenttissueandoftenhaveirregularandulceratedsurfaces.However,clinicalcriteriaaretotallyinadequatefordiagnosisoftumorlikelesions.Atrophy.Areasofatrophymayappearreddenedbecausetheepitheliumisthinandtheconnectivetissuevascularityisclearlymanifested.Theareamaybeslightlydepressed.Specialepithelialstructuresmaybereplacedbyathinepithelium.Forexample,atrophyoflingualpapillaeresultsinasmooth,redtonguesurface.OtherLesions.Certaingrosslesionsthatoccuronskinarenotcharacteristicallyseenonoralmucosa.Amongthesearescars,crusts(driedexudateoverlyinganulceratedarea),fissures(cracksresultingfromdrying),andexcoriations(self-inflictedtraumatizedareas).DISTRIBUTIONANDDURATIONOFLESIONSInadditiontothetypeoflesionpresentinagivencase,thedistributionofthelesionmaybesignificantandmayaidinestablishingatentativediagnosis.Forexample,aneruptionofvesiclesintheposteriorareaofthemouthandoropharynxmightsuggestherpangina,whereasinvolvementoftheanteriorareaofthemouthandgingivamightsuggestherpeticstomatitis.Severevesicularandbullouslesionsonthelabialmucosamightindicateerythemamultiforme.Thedurationoflesionsmayalsobesuggestiveofcertainconditions.Ahistoryofarecurrentpatternmaybevaluableindetectingaproblemsuchasaphthousstomatitis.HIBTOPATHOLOGYOFMUCOSALLESIONSThemicroscopicpictureofmucousmembranediseaseisrarelydiagnosticinitself,butitmaypresentcertainfeaturessuggestiveoforconsistentwithknowndiseasepatterns.Thevarietyofpossiblealterationsaffectingepitheliumandconnectivetissueislimited.Allchangesfromnormalmustberecordedineachcase,andtheassembledfactsmaypointtoaspecificdiagnosis.Incertainlesionssuchasmalignanttumors,adefinitivediagnosiscanbeestablishedbymicroscopicstudy.Histopathologicfeaturescommonlyseeninmucousmembranediseasesarediscussedhereinrelationtoepitheliumandconnectivetissue.EpithelialAlterationsHyperkeratosis.Thisconditionischaracterizedbyawideningorthickeningofthestratumcorneum.Clinically,hyperkeratosisresultsinawhitelesion.Theopacityandwhitenessofthelesionarerelatedtotheamountofkeratinization.Paraketatosis.Inparakeratosis,thestratumcorneumdemonstratespersistenceofnucleiandvaryingdegreesofthickeningthatmayequalthatofhyperkeratosis.Thisreactionmayrepresentanabnormallyrapidkeratinizationprocess.Clinically,itusuallyresultsinawhitelesion.Acanthosis.Inthiscondition,thestratumspinosumbecomeswider.Acanthosissignifiesepithelialhyperplasia;itmayexistwithorwithouthyperkeratosis.Spongiosis.Thistermisusedtosignifyintercellularedemaoftheepithelium,inwhichintercellularbridgesofthestratumspinosumbecomemoreprominent.HydropicDegeneration.Becauseofedemaanddegenerationofcellsofthestratumgerminativum,thenucleiarereplacedbyclearspaces.Entirecellsgraduallydegenerate,andtheepithelialconnectivetissueboundaryispoorlydefined.Acantholysis.Thislesioniscausedbyaseparationofcellsinthestratumspinosumsothatanintraepithelialsplitoccur,whichleadstotheformationofanintraepithelialvesicle.ExtensionofRetePegs.Becauseofelongation,theretepegsextendintounderlyingconnectivetissue.PseudoepitheliomatousHyperplasia.Inthiscondition,theretepegsextendfardownward,usuallyaccompaniedbyacanthosis,tocreateatissuepatternsimilartocarcinoma.However,thecellsareessentiallynormalinsize,shape,andchromaticity.Dyskeratosis.Thislesionshowsanabnormalorientationordevelopmentofepithelialcells.Dyskeratosisormalignantdyskeratosissignifiesapremalignantepithelialchange,andthecellsshowsuchalterationsashyperchromatism,changesinpolarity,andincreasednuclearsizewithprominenceofthenucleoli.Mitoticfiguresmayalsobeincreased.AbenigntypeofdyskeratoticchangeorbenigndyskeratosisoccursinconditionssuchasmolluscumcontagiosumandDarier'sdisease.Generally,however,thetermdyskeratosisisusedonlyforthemalignantvariety,torepresentapremalignantlesion.Necrosis.Necrosisreferstodestructionofepitheliumandreplacementbyanamorphousmassoftissue.Necrosisisusuallyproducedbychemicalactionorbybacterialactivity,asinfusospirochetaldisease.Ulceration.Theulcerationisabreakintheepithelialcontinuityduetodestruction.ConnectiveTissueAlterationsInfammatoryInfiltration.Inchronicinflammatorylesionstheconnectivetissueisinfiltratedbylymphocytes,plasmacells,histocytes,andscatteredpolymorphonuclearleukocytes.Theinflammatoryinfiltratemaybehomogeneouslyspreadthroughouttheconnectivetissue,localizedinabroadbandclosetotheepithelium(asinlichenplanus),orperivascular(asindiscoidlupuserythematosusorsyphilis).Inacuteinflammatorylesions,theprimarycelloftheinfiltrateisthepolymorphonuclearleukocyte.Inulceratedareas,thesurfaceexudatecontainslargenumbersofleukocytes.Thepresenceofeosinophilleukocytesmaysuggestanallergicresponseoraparasiticinfestation,butthesecellsarealsocommonlyseeninhealingmacosallesions.Multinucleatedgiantcellsmaybepresentinaforeignbodyreaction,andspecifictypessuchasLanghans'cellsarehighlysuggestiveofatuberculouslesion.Hyperplasia.Hyperplasiaofconnectivetissueischaracterizedbyanincreaseddensityofcollagenfibers,asindiphenylhydantoin(Dilantin)reaction.CollagenDegeneration.Thisisanimportantconnectivetissuechange,characterizedbya"coagulation"orclumpingofcollagenbundlessothatthefibroustextureisabsent.Thisconditionisseeninradiationlesionsandlupuserythematosus.Vascularity.Thenumberofcapillariesandtheirengorgementwitherythrocytesmaybeincreased.MucousGlandAlterations.Obstructionofmucousglandsbyinflammationmayresultinacinardistentionandductaldilatation.VOCABULARYl.grossly肉眼地2.macroscopic肉眼的3.macule斑(點)4.papule丘疹5.plaque斑塊，血小板6.vesicle小水皰7.bulla大皰8.pustule膿皰9.ulcer潰瘍10.erosion糜爛11.nodule結節(jié)12.tumor腫瘤13.atrophic萎縮14.circumscribed環(huán)狀的15.pinhead帽針頭16.eruption疹17.punctatehemorrhages點狀出血18.petechiae瘀斑19.thrombocytopenicpurpura血小板減少性紫斑20.melanindeposition黑色素沉著21.Addison'sdisease阿狄森病22.vascularmalformation血管畸形23.hereditorytelangiectasia遺傳性毛細血管擴張癥24.ovoid卵形的25.dermatosis皮膚病26.lacelike花邊的27.annular環(huán)狀的28.pebbled卵石的29.crack裂縫30.fissure溝紋31.leukoplakia白斑32.carcinoma癌33.discoidlupuserythematosus盤狀紅斑狼瘡34.vesicalar皰的35.subepithelial上皮下的36.intraepithelial上皮內的37.epithelium上皮38.bleb皰，大皰39.bullous皰的40.pemphigus天皰瘡41.pemphigoid類天皰瘡42.erythemamultifomle多形紅斑43.herpeticstomatitis皰疹性口炎44.drugeruption藥疹45.purulent膿的46.pyostomatitis膿性口炎47.fbrin纖維48.polymorphonuclearleukocyte多形核白細胞49.infiltration浸潤50.acuteinflammatorylesion急性炎性病損51.edge邊緣52.ragged粗糙的53.tuberculosis結核54.indurated硬結的55.elongaged伸長的56.trauma創(chuàng)傷57.rupture裂58.stratumgerminativum生發(fā)層59.fibroma纖維瘤60.neoplasm新生物61.pyogenicum膿62.angiogranuloma血管顆粒瘤63.mandatory強迫性的64.criteria標準65.exoriat