fnh肝局灶性结节性增生.ppt

肝局灶性结节性增生 Focalnodularhyperplasia FNH Outline FNHaccountsforapproximately8 ofallprimaryhepatictumorandisthesecondmostcommonbenignlivertumorafterhemangioma Thisbenigntumouroccursmostcommonlyinwomenaged20 50years butmayoccurinbothmenandwomenatanyage withmultiplelesionsbeingfoundin20percentofcases FNH Oralcontraceptive口服避孕药useisassociatedwithFNHbuttheresponsibilityoforalcontraceptivesintheoccurrenceofthelesionhasnotbeendemonstrated Clinicalsymptoms FNHisusuallyanincidentalfindingatimagingandonlyone thirdarediscoveredbecauseofclinicalsymptomssuchasmildepigastricpainordiscomfortandorpalpableabdominalmass Bloodlivertestsarenormalinhalfofthecasesandshowonlyincreasedinserumgamma glutamyl transpeptidase血清r 谷氨酰转肽酶activityinmostoftheremnants well circumscribedlobulatedmasswithcentralscar arrow andradiatingseptations Pathologicalappearance FNHisdefinedasanodulecomposedofbenign appearinghepatocytesoccurringinaliverthatisotherwisehistologicallynormal FNHisahyperplasticliverparenchyma 增生性肝实质 subdividedintonodulesbyfibrousseptathatmayformstellatescars 星状瘢痕 Thelesionisusuallysolitary 80 andmeasureslessthan5cmindiameter Occasionally FNHispedunculated 蒂 Photomicrographofhistopathologicspecimenshowsregionsofnodularhepatocellularproliferationseparatedbyradiatingbandsandsurroundingmyxomatousscar arrows Themarginissharp oftenlobulatedandnocapsuleispresent Hemorrhageandnecrosisarerare Atmicroscopy thecentralfibroticzoneisdenseconnectivetissue 致密结缔组织 whichcontainsnumerousabnormallythickwalledarteries Markedproliferationofbiliarystructuressurroundedbyinflammatorycellsisobservedwithinandattheperiphery 边缘 ofthefibrousseptae Kupffercellsarealsoseenwithinthelesion FNH classic 80 non classic 20 a telangiectaticFNH b withatypia c mixedhyperplasticandadenomatousFNH Diagnosis CT NonenhancedCTscans FNHisdemonstratedasafocalhypodenseorisodensemasscomparedwithnormalliver Acentralhypodensescarisdepictedinonlyone thirdofthecases Calcificationswithinthecentralscarareveryrareandobservedinonlyabout1 ofthecases contrast enhancedCTscan arterialphase Thelesionenhancesrapidlyinmostcasesandthelesiontolivercontrastishigh Lesioncontouriswelldemarcatedandmaybelobulated Atthattime thecentralscarishypodenseandappearsmoreevidentthanonunenhancedCTscans portalvenousphase lesionenhancementdecreasesandthelesionmaybeeitherisoorslightlyhyperdenserelativetonormalliver Small sizedFNHmaybebarelyvisible whereaslarge sizedFNHarevisualizedduetodeformityinthelivercontourordisplacementofadjacentvesselsordepictionofarelativelyhypoattenuatingcentralscar delayedphase FNHareisodenserelativetonormalliverandinmostcases centralscarsappearisoorhyperattenuating Acentralscarisobservedmoreofteninlargelesionsthaninsmalllesions CT T1WIT2WI Diagnosis MRI NonenhancedMRIscans TypicalFNHsareisoorhypointenseonT1WIandisoorslightlyhyperintenseonT2WI ThecentralscarishypointenseonT1WIandstronglyhyperintenseonT2WI contrast enhancedMRIscan dramaticenhancementinthearterialphase followedbyisointensityofthelesionduringtheportalvenousphase Ondelayedphaseimaging thecentralscarshowshighsignalintensity Atypicalforms scarsareseeninmorethan80 ofcases However radio pathologicpapershavedemonstratedthatsomeFNHmayhavenoscarevenatpathologyespeciallyFNHmeasuringlessthan3cmindiameter Rarely scarsremainhypodenseorisodenseondelayedscansorarehypointenseonT2 weightedimages Thesefindingsmaybeobservedupto20 ofcases NearlyallFNHsarehypervascularatthearterialphaseoftheenhancement butlesionenhancementmayvaryattheportalphaseorondelayedimages Bothhypodensityorintensityofthemassondelayedphase oronbothportalveinanddelayedphaseimagesaswellashyperdensity intensityofthemassontheportalveinphaseoronbothportalveinanddelayedphasesmaybeseen AlthoughFNHisanon encapsulatedlesion capsulelikeenhancementmaybeobservedonportalveinandondelayedphasescansinabout25 36 ofthecases Thepseudocapsule 假包膜 ishypointenseonT1andslightlyhyperintenseonT2 Differentialdiagnosis 肝囊肿Hepaticcyst 原发性肝癌primaryhepaticcarcinoma 肝囊肿Hepaticcyst noncontrast enhanced contrast enhan