FNH肝局灶性結(jié)節(jié)性增生

Outline

FNHaccountsforapproximately8%ofallprimaryhepatictumorandisthesecondmostcommonbenignlivertumorafterhemangioma.

Thisbenigntumouroccursmostcommonlyinwomenaged20–50years,butmayoccurinbothmenandwomenatanyage,withmultiplelesionsbeingfoundin20percentofcases.FNH當(dāng)前1頁，總共25頁。

Oralcontraceptive口服避孕藥useisassociatedwithFNHbuttheresponsibilityoforalcontraceptivesintheoccurrenceofthelesionhasnotbeendemonstrated.當(dāng)前2頁，總共25頁。ClinicalsymptomsFNHisusuallyanincidentalfindingatimagingandonlyone-thirdarediscoveredbecauseofclinicalsymptomssuchasmildepigastricpainordiscomfortandorpalpableabdominalmass.Bloodlivertestsarenormalinhalfofthecasesandshowonlyincreasedinserumgamma-glutamyl-transpeptidase血清r-谷氨酰轉(zhuǎn)肽酶activityinmostoftheremnants.當(dāng)前3頁，總共25頁。

well-circumscribedlobulatedmasswithcentralscar(arrow)andradiatingseptations.

Pathologicalappearance當(dāng)前4頁，總共25頁。FNHisdefinedasanodulecomposedofbenign-appearinghepatocytesoccurringinaliverthatisotherwisehistologicallynormal.FNHisahyperplasticliverparenchyma（增生性肝實質(zhì)）subdividedintonodulesbyfibrousseptathatmayformstellatescars（星狀瘢痕）.Thelesionisusuallysolitary(80%)andmeasureslessthan5cmindiameter.Occasionally,FNHispedunculated(蒂).當(dāng)前5頁，總共25頁。Photomicrographofhistopathologicspecimenshowsregionsofnodularhepatocellularproliferationseparatedbyradiatingbandsandsurroundingmyxomatousscar(arrows).當(dāng)前6頁，總共25頁。Themarginissharp,oftenlobulatedandnocapsuleispresent.Hemorrhageandnecrosisarerare.Atmicroscopy,thecentralfibroticzoneisdenseconnectivetissue（致密結(jié)締組織）whichcontainsnumerousabnormallythickwalledarteries.Markedproliferationofbiliarystructuressurroundedbyinflammatorycellsisobservedwithinandattheperiphery（邊緣）ofthefibrousseptae.Kupffercellsarealsoseenwithinthelesion.當(dāng)前7頁，總共25頁。FNHclassic(80%)non-classic(20%)

(a)telangiectaticFNH,

(b)withatypia,

(c)mixedhyperplasticandadenomatousFNH

當(dāng)前8頁，總共25頁。Diagnosis（CT）Nonenhanced

CTscans

FNHisdemonstratedasafocalhypodenseorisodensemasscomparedwithnormalliver.Acentralhypodensescarisdepictedinonlyone-thirdofthecases.Calcificationswithinthecentralscarareveryrare

andobservedinonlyabout1%ofthecases.當(dāng)前9頁，總共25頁。contrast-enhancedCTscanarterial

phaseThelesionenhancesrapidlyinmostcasesandthelesiontolivercontrastishigh.Lesioncontouriswelldemarcatedandmaybelobulated.Atthattime,thecentralscarishypodenseandappearsmoreevidentthanonunenhancedCTscans.當(dāng)前10頁，總共25頁。

portalvenousphaselesionenhancementdecreasesandthelesionmaybeeitherisoorslightlyhyperdenserelativetonormalliver.Small-sizedFNHmaybebarelyvisible,whereaslarge-sizedFNHarevisualizedduetodeformityinthelivercontourordisplacementofadjacentvesselsordepictionofarelativelyhypoattenuatingcentralscar.當(dāng)前11頁，總共25頁。

delayed

phase

FNHareisodenserelativetonormalliverandinmostcases,centralscarsappearisoorhyperattenuating.Acentralscarisobservedmoreofteninlargelesionsthaninsmalllesions.當(dāng)前12頁，總共25頁。CT當(dāng)前13頁，總共25頁。T1WIT2WI

Diagnosis（MRI）NonenhancedMRIscans

TypicalFNHsareisoorhypointenseonT1WIandisoorslightlyhyperintenseonT2WI.

ThecentralscarishypointenseonT1WI

andstronglyhyperintenseonT2WI.當(dāng)前14頁，總共25頁。contrast-enhancedMRIscan

dramaticenhancementinthearterialphase,followedbyisointensityofthelesionduringtheportalvenousphase.Ondelayedphaseimaging,thecentralscarshowshighsignalintensity.

當(dāng)前15頁，總共25頁。Atypicalforms當(dāng)前16頁，總共25頁。scarsareseeninmorethan80%ofcases.However,radio-pathologicpapershavedemonstratedthatsomeFNHmayhavenoscarevenatpathologyespeciallyFNHmeasuringlessthan3cmindiameter。當(dāng)前17頁，總共25頁。

Rarely,scarsremainhypodenseorisodenseondelayedscansorarehypointenseonT2-weightedimages.Thesefindingsmaybeobservedupto20%ofcases.

NearlyallFNHsarehypervascularatthearterialphaseoftheenhancement,butlesionenhancementmayvaryattheportalphaseorondelayedimages.Bothhypodensityorintensityofthemassondelayedphase,oronbothportalveinanddelayedphaseimagesaswellashyperdensity-intensityofthemassontheportalveinphaseoronbothportalveinanddelayedphasesmaybeseen.當(dāng)前18頁，總共25頁。

AlthoughFNHisanon-encapsulatedlesion,capsulelikeenhancementmaybeobservedonportalveinandondelayedphasescansinabout25–36%ofthecases.Thepseudocapsule(假包膜)ishypointenseonT1andslightlyhyperintenseonT2.當(dāng)前19頁，總共25頁。

Differentialdiagnosis肝囊腫Hepaticcyst

原發(fā)性肝癌primaryhepaticcarcinoma當(dāng)前20頁，總共25頁。肝囊腫Hepaticcystnoncontrast-enhancedcontrast-enhancedCTnonenhancement當(dāng)前21頁，總共25頁。肝囊腫Hepat