Challenges in PancreaMc Cytology - Moffitt Cancer Center

ChallengesinPancrea.cCytology

BarbaraA.Centeno,M.D.SeniorMemberandDirectorofCytopathology/MoffittCancerCenterandResearchInstitute

Professor/DepartmentsofOncologicSciencesandPathologyandCellBiologyattheUniversityof

SouthFloridaCollegeofMedicine

Disclosures�  Ihavenothingtodisclose

Challenges� Diagnosisofductaladenocarcinoma� Diagnosisanddifferentialdiagnosisofnonductalneoplasms

� Cytologyofpancreaticcysticlesions

Case1�  54yomalepresentedwithabdominalpain.Imagingshowedamassintheheadofthepancreas.Theimagingfindingsweresuggestiveofpancreatitis,butadenocarcinomawasnotexcluded.

Whatisyourdiagnosis?

Challenge� Benign,nonneoplasticinflammatorychangesfromductaladenocarcinoma

�  Lessfrequentcomponentthanacinarcells

� Occurinflat,monolayeredorhoneycombsheetswithuniformlyspacednuclei

�  Rounduniformlysizednuclei

�  Cytoplasmcuboidaltocolumnar,largerductscontainmoremucin

CytologyOfNormalDucts

CytologyOfAcinarCells� Majorityofnormalpancreas

� Occurinacini,singlecellsorstrippednuclei

�  Abundantwell-defined,pyramidalortriangularshaped,densecytoplasm

�  Cytoplasmcontainzymogengranules,whicharepositivewithperiodicacidSchiffstains

�  Nucleihavecharacteristicprominentnucleoli

NormalIsletCells

Contaminants�  Squamouscells� Mesothelialcells� Hepatocytes� Gastricepithelium�  Smallintestinalepithelium

� Largeflatsheets� Cytoplasmoffoveolarcellsiscolumnar,withmucin

� Nucleiroundandevenlyspaced,uniforminsize

Gastric Epithelium

GastricEpithelium

• Sometimes show small grooves, inclusions and small nucleoli • Associated with mucin

Gastric Parietal Cells and Chief Cells

Pitfall: May be mistaken for acinar cells or hepatocytes

DuodenalEpithelium

� Nucleiroundanduniform

� Backgroundmucinistypicallythin,associatedwithgroups,mayhavedebris

Enterocytes have a microvillous brush border

Degenerated duodenal cells

ChronicPancrea..s

Fibrous tissue fragments

Ductal cells

*absent acinar cells

Calcifica.ons

Atypiainductalcells:Cellsremainin2-dimensionalsheet,increasednuclearsize,membranesregular

CriteriaforDuctalAdenocarcinoma�  Cellularity�  Background

�  Coagulativenecrosisorinflammationormucin�  Maybeclean

�  Architectural�  Three-dimensionalgroups,lossofpolarity,abnormalacinarstructures,

cribiforming�  Nuclear

�  nuclearenlargement�  IncreasedN/C�  Irregularnuclearmembranes�  Irregularchromatin

�  Cytoplasmic�  Mucinisabnormal�  Cytoplasmicvacuoles

�  Dyshesion�  Singlecells�  Peripheraldyshesion

�  Mitoses�  Morefrequent�  abnormal

CYTOLOGICALEVALUATION

� Lowpower:Assesscellularity,compositionandbackground

�  Malignancymorecellular�  Predominantlyductalratherthanmixed(appliesto

intraoperativeaspirates)�  Coagulativetumortypenecrosis

AdenocarcinomaTypicalSmear

Low power view Intermediate power of same field

Background

Coagulative necrosis Inflammation

Clean Mucinous

CYTOLOGICALEVALUATION

� Intermediatepower:Assessarchitectureofgroups(mostcritical*)

�  Abnormalspacingofnucleiformingeither3-dimensionalcrowdedgroupsorexaggeratedhoneycombgroups,lossofpolaritY,Dispersedsinglemalignantcells

Nuclei crowded, touching

Architecture Pseudoacinar structure

Crowded nuclei

Crowded nuclei

ADENOCARCINOMAUnevenspacingofnucleiingroups

�  Thenucleibecomeunevenlydistributed,crowdedandtouchinginsomeareasandveryseparatedinothers

�  Theexaggeratedhoneycombpatternisproducedingroupswithabundantcytoplasmicmucininwhichthenucleiareunevenlyspaced,asabove.

CYTOLOGICALEVALUATION

� Highpower:Assesscytoplasmicandnucleardetails

�  Anisonucleosis(4:1),nuclearenlargement(1.5Xredbloodcells),nuclearmembraneabnormalities,parachromatinclearing,hypoandhyperchromasia

NuclearFeature:Anisonucleosis

Nuclear size variation greater than 4:1

Nuclearenlargement

Nuclei >1.5 X RBC

Adenocarcinoma nuclei (top) compared to normal ducts (bottom)

Abnormalchroma.ndistribu.on

� Hypochromasia:subtle,diffusepalenesstothenucleus.

•  Hyperchromasia •  Abnormal parachromatin

clearing

Cytoplasmic vacuoles or cytoplasmic lumens

• On edge, nuclei appear pseudostratified

Adenocarcinoma: cytoplasmic mucin, nuclear enlargement, pseudostratification

SingleMalignantCells

Mitotic figures

BenignVsAdenocarcinomaFeature Benign AdenocarcinomaComposition mixedductalandacinar mostlyductalCellularity scant(exceptGI) moderatetohighArchitectureofgroups flatandcohesive irregularshapeLossofpolarity absent presentNuclearcrowding minimal presentNuclearmembrane round,oval angulation,

elongation, notches,grooves,

convolutionsN/C maintained increasedChromatin even,finelygranular parachromatin

clearing maybepale irregular,

coarseMitoses minimal/normal present/atypical

formsSingleatypicalcells absent presentNuclear enlargement minimal atleast>1.5X

normalAnisonucleosis minimal 4:1

Gastric epithelium lacks anisonucleosis, nuclear enlargement, nuclear membrane irregularity and crowding and loss of polarity

Gastric Adenocarcinoma

Acinar formation, nuclear enlargment slight irregularities in adenocarcinoma

Adenocarcinomawithabundantinflamma.on

Case1:Diagnosis� Adenocarcinomainabackgroundofpancreatitis

Case2�  42yomalepresentswithahypoechoic,well-definedlesioninthepancreas.EUS-FNAisperformed.

Imagesforcase2

Whatisyourdiagnosis?

Challenge� Diagnosisandwork-upofnonductalneoplasms

NonductalNeoplasms

� SolidCellularNeoplasmCytology� Monomorphic,cellularsmears� Dyshesive,numeroussinglecells�  Vascular

Pancrea.cNeuroendocrineTumors

•  Tumorswithneuroendocrinephenotype

•  Cytology•  Monomorphiccellpopulation•  Uniformlycellularsmears•  Dispersed,dyshesivecells

Pancrea.cNeuroendocrineTumor

• Loose aggregates

Pseudorosettes

Vacuolated

Scant and wispy

Plasmacytoid

Granular

Cytoplasm

Salt and pepper chromatin

May have prominent nucleoli

Pancreatic Neuroendocrine Tumor Vascular Pattern

PoorlyDifferen.atedNeuroendocrineCarcinoma

AcinarCellCarcinoma�  Tumorswithacinarphenotype�  Abundantcytoplasmwith

granules�  Largenucleiwithprominent

nucleoli�  PASstainsdemonstratezymogen

granules�  NegativeimprintonDiff-Quik

AcinarCellCarcinoma

�  Largeandsmallgrape-likeclusters

�  Uniform,likenormalacinarcells

• Smears richly cellular • Single cells, stripped nuclei

• Grape Like clusters • Loosely cohesive • Monomorphic

• Vascular

AcinarCellCarcinomaProminentNucleoli

SolidPseudopapillaryNeoplasm(SPN)

Capillary Mucinous stroma surrounding capillary Neoplastic cells

Mucin seen on Diff Quik

Stromal pattern may resemble adenoid cystic carcinoma.

Mucinous stroma is pathognomic!

PAS shows mucin

�  Thenucleiaremonomorphic,withsmallnucleoli

�  Thecytoplasmisscantandamphophilic

�  Smallnucleoli,grooves,indentations

Some cells have a cytoplasmic tail.

IHC:PanNETVS.ACCVSSPPNPanNET ACC SPPN

Pan CK + + -/+

CK7 + + -

CK20 +/- - -

Vimentin - -/+ ++

NSE + - ++

β-catenin (nuclear-cytoplasmic)

- + +

α1AT, α1ACT - + +

CD 10 -/+ +/- +

CD 56 + - + focal

Trypsin, chymo-trypsin, bcl10

- + -

Synaptophysin, chromogranin

+ - + focal

Β Catenin

NormalAcinivs.ACC

PiYall:MistakingPanNETforAdenocarcinoma� PanNETmayshowprominentnucleoliandpseudoacini,mimickingadenocarcinoma(top).

� Bottomshowsmorenuclearvariabilityandlossofsaltandpepperchromatin.

Neuroendocrinecarcinomainterpretedasadenocarcinoma

AcinarCellCarcinomaMistakenasAdenocarcinoma

Adenocarcinomavs.PanNETorACC

Case3�  65yofemalepresentedwithcysticmassinthepancreas.EUS-guidedFNAwasperformed.

ImagesofCase3

Whatisyourdiagnosis?

Challenge� DiagnosisandWorkupofCysticLesions

Cys.cAndIntraductalLesions�  Pseudocysts/RetentionCysts�  Congenital/Hereditary

�  simpleorsolitarytruecysts,polycysticdiseases�  Infectious�  Neoplastic(1-5%allexocrineneoplasms)

�  Inherentlycystic�  serouscystadenomaandmucinouscysticneoplasms

�  Neoplasmswithcysticdegeneration�  Intraductalneoplasms

�  Nonneoplastic/Miscellaneous�  Lymphoepithelialcysts�  Squamouscystofthepancreaticducts

Pseudocyst

Cys.cNeoplasms�  InherentlyCystic

�  SerousCystadenoma� MucinousCysticNeoplasm

�  IntraductalNeoplasms�  IntraductalPapillaryMucinousNeoplasm

�  SolidNeoplasmsWithCysticDegeneration�  SolidPseudopapillaryNeoplasm�  CysticPancreaticNeuroendocrineTumors

SerousCys.cNeoplasmTypicalhistopathologyandcytopathology

•  Gross: Scant fluid •  No mucin*

SerousCys.cNeoplasmsCytology

MucinousCys.cNeoplasmClassichistopathology

� Linedbytall,columnar,mucincontainingepithelium�  pancreatobiliaryphenotype

� Epitheliummayshowgobletcellsandneuroendocrinecells

� Liningmayshowlow,moderateorhighgradedysplasia

� Ovariantypestromakeytodiagnosis

IntraductalPapillaryMucinousNeoplasmClassichistopathology

•  Papillary proliferation along the ducts •  Thin, fibrovascular cores

Mucin

Neoplastic epithelium

•  Gross: viscid, clear to white fluid, may have visible strands of mucus

Typical cytology of IPMT or MCN

Mucinousbackground

Mucinousbackground

IPMNBackgroundInterpretation:ThickbackgroundmucinwithoncoticcellsDiagnosticcategory:Neoplasm:otherComment:Noneoplasticepitheliumispresentforevaluation

MucinSpecialStains

IPMN/MCNBackground

Psammomatouscalcifica.onsafeatureofIPMN

Neoplas.cMucinousCyststhick,colloidlikemucininbackground

Neoplas.cepithelium

IPMNArchitecture

IPMNIrregularSpacingNuclear

IPMN/MCNCytoplasmCytoplasm

Cytoplasm may be finely vacuolated

IPMN/MCNNuclearfeatures� Hypochromasia�  Subtlenuclearmembraneabnormalities

� Nucleoli,peripherallylocated,similartopapillarycarcinoma

�  Intranucleargroovesandinclusionsdiagnostic

IPMN/MCNIntranuclearinclusionsonDiff-Quik

IntraductalOncocy.cPapillaryNeoplasm

IOPNcellblock

Roleofcytology� Differentiatemucinousfromnonmucinouslesions� Assessriskofmalignancy

AncillaryStudiesinPancrea.cCystFluid�  Viscosity

�  ElevatedinMCN/IPMN/IOPN�  CEA

�  Elevatedinmucinousneoplasms�  Remainsthestandardforseparatingmucinousfromnonmucinouscysts

�  Falsepositivesforsomenonmucinouscysts,suchasLCOP�  Amylase

�  Elevatedinpseudocyst,andintraductalpapillarymucinoustumors�  Lowinserouscystadenomaandmucinouscysticneoplasm

� Mutationalanalysis�  KrasdetectedinIPMNandMCN

�  AlsoindilatedPanIN

�  GNASinIPMN

CriteriaforMucinousCyst�  Fluidviscous,clearorwhite� Cytologyshowsmucinousbackgroundasdescribed,+/-neoplasticepithelium

� Ancillarystudies�  CEAelevated� Mutationalanalyses

�  Krasmutated�  GNASmutationsinIPMN

IPMNBackground

Cytopathology report: Thick background mucin, histiocytes, and oncotic cells, consistent with IPMN or neoplastic mucinous cyst Comment: No neoplastic epithelium is present for evaluation of dysplasia

GIEpitheliumvsIPMNMucinisdifferent

GastricFoveolarvsIPMNLGGastricFoveolarepithelium IPMNwithfoveolarlining

IPMN/MCN GastricFoveolarepithelium

Cup shaped mucin

Gastrointes.nalBackgroundvs.Neoplas.cBackground

Duodenal Neoplastic

Neoplas.cMucinousEpitheliumvs.GastricEpithelium

IPMN:irregularspacing Gastric:Regularspacing

Gastric

Neoplas.cMucinousEpitheliumVS.GastricIPMN:Papillary Calibri

GastricEpitheliumStrippedNuclei

Degenerative grooves

Inclusions

Mucin and stripped nuclei

LowGradeDysplasia

Basally located nuclei

Abundant columnar mucin containing cytoplasm

Columnar cytoplasm with mucin

Basally located nuclei

Moderatedysplasia

Pseudostratification

High-GradeDysplasia

Papillary tufts, nuclei extend to luminal border

Mitoses

Is it IPMN or gastric foveolar epithelium?

Mucinous epithelium present: possibly gastric or neoplastic, Negative for high grade dysplasia

Is there characteristic background mucin?

Evaluate for neoplastic cells Does the aspirate show neoplastic cells?

Descriptive

Report if there is high grade dysplasia

Descriptive

Work-up as a solid lesion

YES NO

NO CELLS CELLS PRESENT YES NO

Algorithmic Approach for the Cytological Evaluation of Pancreatic Cysts

Summary� Utilizeanalgorithmicapproachbeginningwithreviewofclinicalandimagingfindings,thiswillestablishthecytologicalalgorithm

� DiagnosisofAdenocarcinoma� Qualitativeandsemi-quantitativeapproach

� Nonductalneoplasms� Overlappingmorphologicalfeatures�  Ancillarystudiesbeneficial

� Cysticneoplasms� Differentiatemucinousfromnonmucinous�  Identifyhighriskcysts