Pitfalls In The Diagnosis Of Well-differentiated HCA Vs .

7/27/20132013 Colorado Society of PathologyPitfalls in the diagnosis ofwell-differentiatedhepatocellular lesionsOutline Hepatocellular adenoma: new WHOclassification HCA vs. focal nodular hyperplasiaHCA vs. well-differentiated HCCSanjay Kakar, MDUniversity of California, San FranciscoBenign hepatocellular lesions: pre-1990 Focal nodular hyperplasia Hepatocellular adenomaFNH vs. HCACentral scarFibrous ocal nodularhyperplasiaPresentTypically presentPresentHepatocellularadenomaAbsentTypically absentAbsentGenerally prominentAbsentPolyclonalMonoclonalBenign hepatocellular lesions: 1990sTelangiectatic FNH Focal nodular hyperplasiaTelangiectatic FNH Hepatocellular adenoma1

7/27/2013Telangiectatic FNHHepatocellular adenomaThe French Revolution Clonality studies: Monoclonal Protein profiling: cluster with adenomas Imaging: resembles adenomaReclassified as telangiectatic adenoma Ductular reaction Fibrous septa with dystrophic arterioles Telangiectasia, inflammatory infiltrateParadis, Gastroenterology, 2004Benign hepatocellular lesions: pre-2008 Focal nodular hyperplasia Hepatocellular adenomaTelangiectatic or variant adenomaHepatology. 2006;43:515-24HCA: WHO classification oryHNF-1α mutationβ-catenin mutationJAK/STAT pathwayWomen, OC useFamilial40% in menAndrogensWomen (OCs), menObesity, diabetesMarked steatosis, noatypiaPseudoacinar,cytologic atypia, smallcell changeInflammation,sinusoidal dilatation,ductular reactionHCC rareHCC �-cateninmutatedMutation –veInflammatoryMutationnegativeMutation –veNon-inflammatoryIL-6 receptorsignallingMutation-negative cases Inflammatory: Similar to telangiectatic adenoma Non-inflammatory: no inflammation or sinusoidaldilatation2

7/27/2013Hepatocellular adenomaThe French Revolution2006: part 2Hepatology. 2007 ;46:740-8HCA: α mutatedβ-cateninmutated Women Steatosis Atypia, risk of HCC:minimal Fatty acid bindingprotein absentFatty acidC-reactive protein (CRP) β-cateninbindingSerum amyloidGlutamineprotein (FABP) associated protein (SAA) synthetase (GS)FABP negativeCRP SAA Nuclear βcateninDiffuse GSUnclassified (5-10%): no known defining featuresβ-catenin mutatedHCA: d-Fatty acidbinding protein(FABP)β-cateninGlutaminesynthetase (GS)FABP negativeNuclear β-cateninDiffuse GSInflammatory-C reactive protein (CRP)-Serum amyloid associatedprotein (SAA)Unclassified40% menCytologic atypia, frequent association with HCCNuclear translocation of β-cateninNo definingfeaturesCRP SAA 3

7/27/2013Normal liver:perivenular GSβ-catenin-activatedadenoma: diffuse GSHCA: genotype-phenotypeHNF1-mutatedInflammatory hepatocellular adenomaBeta-cateninmutatedInflammatory-Fatty acid bindingprotein (FABP)-Beta-catenin-Glutamine synthetase(GS)FABP negativeNuclear beta-cateninDiffuse GS-C reactive protein (CRP)-Serum amyloidassociated protein (SAA)CRP SAA SAA in inflammatory udo-PTHCA: WHO classification 2010HNF-1αinactivatedInflammatory35-50%Women, OC use40-50%Women (OCs), menObesity, diabetesMarked steatosis,no atypiaHCC rareFABP negativeHCA ated10%40% in menAndrogens, glycogenstorage diseaseInflammation,Pseudoacinar, smallsinusoidal dilatation,cell changeductular reactionHCC rareHCC 40%SAA positiveNuclear β-cateninCRP positiveDiffuse nactivatedInflammatory cytoplasmic c negativenuclearcytoplasmic negativemembranousperivascularUnclassified (5-10%): no known defining features4

7/27/2013Case 1: Obese 42/F with multiple ( 15) liver lesions;largest (4 cm) was biopsiedL-FABPGSL-FABP in lesionL-FABP in normal liverSAADiagnosisHNF1α-inactivated hepatocellular adenomaHepatic adenomatosis By definition, 10 adenomasYoung womenMost are HNF1α-inactivated or inflammatoryPathogenesisObesity, less strong association with OCsGerm line HNF1α mutationsManagement of HCAManagementTumor characteristicsResectionWomen: solitary HCA 5 cmMen (?women 50 years): all casesβ-catenin activatedGlycogen storage diseaseConservative withSolitary HCA 5 cmannual surveillanceConservative with Multiple HCAs or adenomatosis,annual surveillancedepending on size5

7/27/2013Case 2: 53/M, 6 cm liver massSAA positiveGS diffuseQuestionsβ-catenin membranous, GS diffuse Does this represent β-catenin activation?SAA and GS diffuse Is this inflammatory HCA or β-cateninactivated HCA?Beta-catenin: membranousGS: diffuse 15% of β-cateninactivated HCA Most have βcatenin mutation Nuclear β-cateninfocal or belowthresholdInflammatory HCA10% have β-cateninactivationGS: diffuseSAA positiveDiagnosisInflammatory HCA with β-catenin activation6

7/27/2013Immunostaining variations in HCAVariationInterpretationMembranous β-catenin, diffuse GSSAA positive, diffuse GS, nuclearβ-cateninNuclear β-catenin in few tumorcellsLFABP patchy; negative in someareasMorphology not typical ofinflammatory HCA, SAA positiveInflammatory HCA by morphology,SAA negativeβ-catenin activationβ-catenin activationβ-catenin activationDoes not support HNF1αinactivated HCAInflammatory HCAOutline Hepatocellular adenoma: new WHOclassification HCA vs. focal nodular hyperplasiaHCA vs. well-differentiated HCCInflammatory HCACase 3HCA vs. FNH: clinical significanceFocal ticNo surgery in most casesNeoplasticSurgery if high riskfeatures: Male, size 5 cmRisk of hemorrhage,associated HCCLarge, symptomatic,atypical features 32 year old woman on OCs Ultrasound for workup of abdominal pain 5 cm liver mass, suggestive of FNHFNH or inflammatory HCAFor FNHFor inflammatoryHCAImaging favors FNHAberrant arterioles in fibrous septaDuctular reactionSinusoidal dilatationInflammationInflammationArteriolesFew ductulesSinusoidal dilatation7

7/27/2013GS: map-like patternFNH or inflammatory HCAImmunostainInflammatory HCAFNHSerum amyloid A(SAA)Glutaminesynthetase (GS)Moderate to strongAbsent/focalβ-catenin activated: diffuseOthers: Perivascular/patchyMap-likeDiagnosis: Focal nodular hyperplasiaGSSAAHistologicfeatureFNHInflammatory p ibrous bandsDuctularreaction18%83% 0.00140%21%90%83%60%57%26%43%0.080.001 0.001 0.001Joseph/Kakar, USCAP meeting 2011GS: map-likeGS: normalFNH vs. IHCA: challenges in interpretation Map-like GS patterns on needle biopsiesMap-like vs. diffuse GS pattern‘Pseudo map-like’ patternSAA in FNH and adjacent liverUse of CRP in addition to SAA8

7/27/2013Case 4: 40F with 6 cm liver massGS: Focal map-likepattern in FNHGSGSGSSAAGS: map-like vs diffuseGS: perivascular and patchy expanded stainingInflammatory HCA with SAA GS: ‘pseudo map-like’Joseph/Kakar, USCAP 20119

7/27/2013GS: “Pseudo map-like”Case 5: 37F with 4 cm liver mass Confined to periphery Patchy and variable Broad hepatocyte groups withuniform strong staining absentHE stainSAA SAA in adjacent liverFNH with map-like GS and SAA GSGSSAASAAFNHRole of CRPGSSAASAA and CRP in IHA and FNHSAA ( 50%)CRP ( 50%)IHAFNH80%5-10%100%20-25%Joseph/Kakar/Ferrell, Mod Pathol 201310

7/27/2013Metastatic adenocarcinomaFNHFNH-like lesionMorphology and GS staining similar toclassic FNH Adjacent to tumors Cirrhosis Vascular abnormalitiesMetastatic adenocarcinomaFNH: Map-like GSHCC vs. hepatocellular adenomaCase 6* 60/M with diabetes and renal failure CT showed a 3.9 cm mass, concerning for HCCor metastatic carcinoma, but appearance wasnonspecific and can represent hepatocellularadenoma11

7/27/2013Reticulin stainInternational Working PartyAdenomaWide plates ( 3)Small cell changeCytologic atypiaReticulinNormalWD-HCC -/ FragmentedFerrell et al, Hepatology 1995Combined immunostainingGlutamine synthetaseHSP 70HSP70, GS and GPC-3: HCA vs. HCCStudyResultsLagana et al, ApplImmunohistochemMol Morph, 2012HSP70, GPC-3 50% sensitivity100% specificGS80% sensitivity50% specificHSP70 in 13% of HCAOverall limited utilityNguyen/Kakar,USCAP, 2012Case 6: 58/M with 5 cm hepatic mass: biopsy58/M with 5 cm liver mass: resection12

7/27/2013Reticulin stainHCA or HCCFor HCAFor HCC61/M with 3.0 cm liver mass (3 yrs later)Beta-cateninThin cell platesLack of cytologic atypiaIntact reticulinAge 50 yearsMale genderWell-differentiated HCCFISHGS.CEP1 gainCEP8 gainKakar/Ferrell, Histopathol, 2009, FISH by JP Grenert, UCSF13

7/27/2013β-catenin activated HCA, orβ-catenin activated HCCMorphology*Atypia:70%HCC*What makes a tumor malignant?Cytogenetics**Concurrent /follow-up: Chromosomal changes:40%60%SourceDefinitionWebster MedicalDictionaryStedman MedicalDictionaryDorland MedicaldictionaryRobbins’PathologyAbility to invade localtissuesAbility to spread to distantsites (metastasize)*BSage, Hepatol 2008Evason/Kakar, Human Pathol 2012**High risk factorsIs β-catenin activated ‘HCA’ malignant? Local invasion (recurrence)MetastasisPathologic featuresSupportive evidenceYesYesYes/noYesFocal atypicalAge/gendermorphologyPseudoacinar Male genderSmall cellOlder agechange( 50 yrs)Thick platesReticulin lossImmunostainingNuclear β-cateninDiffuse GSWell-differentiated hepatocellular neoplasm withatypical features, HCC orβ-catenin activated hepatocellular adenomaHCC arising in adenomaMost β-catenin activated hepatocellular tumors can be diagnosedas HCC with careful attention to morphology and reticulin stainingpattern, especially in resection specimens.*14

7/27/2013ReticulinGSMinimum stainsHCC in adenomaAdenomaPresence of HCCStoot, HPB, 2010studies from 1970-2009Size 5 cm 5 cm68/1635 4%StainReticulinGSInterpretationLoss: HCCDiffuse: β-catenin activationMap-like: FNHOther patterns: HCAInflammatory HCA 95% 4%SAAWell-differentiated hepatocellular lesionStainUtilityReticulinHCCSAAInflammatory HCAGSMap-like: FNHDiffuse: Beta-catenin mutatedStainUtilityLFABPBeta-cateninCRPGlypican-3, HSP70HNF1-alpha inactivated HCABeta-catenin mutatedInflammatoryHCCImaging featuresFNHCentral scarContrast CTenhancementMRI TI-weightedMRI T2-weightedPresentEarly entHeterogeneous andpersistentHyperintensityStronghyperintensity15

7/27/2013FeatureSAA staining in peritumoral liver inneedle biopsy that missed the lesionSAA negative in a lesion that showstypical features of IHASAA positive in a lesion that showstypical features of FNHPitfallMisinterpreted as evidence of IHA,especially when other peritumoralfeatures like inflammation, sinusoidaldilatation and ductular reaction are alsopresentMisinterpreted as absolute evidenceagainst IHAMisinterpreted as IHAPerivenous and patchy GS in a lesion that Misinterpreted as map-like pattern ofshows typical features of IHAFNHDiffuse GS stainingMisinterpreted as map-like pattern ofFNHPseudo-map like GS patternMisinterpreted as map-like pattern ofFNHApproachSAA is not specific for IHA.Interlobular bile ducts and absence ofdiffuse CD34 staining can help inconfirming that the biopsy comprisesnon-neoplastic liver.SAA can be negative in 5-10% of IHA.Imaging and absence of map-like GSstaining is needed to confirm IHA inthese cases.Focal SAA can be seen in 15% of FNH.Map-like GS confirms FNH irrespectiveof SAA .This staining is common in IHA. It isdistinguished from map-like pattern by(i) lack of anastamosing pattern ofstaining.(ii) staining is heterogeneous and weakcompared to homogeneous strongstaining in map-like pattern.Diffuse GS is seen in beta-cateninactivated tumors and does not have areasof periseptal sparing of map-like pattern.Most also show nuclear beta-catenin.This is seen at the periphery of IHA and10% of FNH . When seen in biopsies, itis more likely to be FNH. Diagnosis onneedle biopsy may remain indeterminateif imaging and SAA are not helpful.FNH vs. IHCAGS: map-likeSAA: negativeor positiveGS: resemblesmap-like, butnot typicalSAA: negativeFNHMorphologyand imagingCompatiblewith FNHFNHNot typical ofFNHIndeterminateGS: perivascularand/or patchySAA positiveIHCAGS: diffuseSAA: positiveSAA negativeβ-cateninactivatedIHCAMorphology andimagingConsider CRPLikely SAAnegative IHCA16

Hepatocellular adenoma: new WHO classification HCA vs. focal nodular hyperplasia HCA vs. well-differentiated HCC HCA vs. FNH: clinical significance Focal nodular hyperplasia Hepatocellular adenoma Non-neoplastic Neoplastic No surgery in most cases Surgery if high risk features: Male, size 5 cm Large, symptomatic, atypical features