New Frontiers in PathologyNew Frontiers in PathologyGU case presentationGU case presentation

Rajal B. Shah, M.D.Rajal B. Shah, M.D.Associate Professor - Pathology and UrologyAssociate Professor - Pathology and Urology

Case 13Case 13

A 65 year-old white American male with A 65 year-old white American male with serum PSA of 4 ng/ml, underwent serum PSA of 4 ng/ml, underwent extended 12 core biopsiesextended 12 core biopsies

34βE12 + p63

P504S

P504S

Summary of atypical findingsSummary of atypical findings

Disorganized growth patternDisorganized growth pattern

Presence of some round and poorly Presence of some round and poorly formed small glandsformed small glands

Micro nucleoliMicro nucleoli

Lack of basal cell staining in some glandsLack of basal cell staining in some glands

AMACR reactivityAMACR reactivity

DiagnosisDiagnosis

Benign prostate parenchyma with focus of Benign prostate parenchyma with focus of partial atrophypartial atrophy

Diagnosis of Limited Cancer in Prostate Biopsy: Critical Issues

Recognize cancer and avoid under-Recognize cancer and avoid under-diagnosis (false negative) diagnosis (false negative)

Recognize benign mimics and avoid Recognize benign mimics and avoid over-diagnosis (false positive)over-diagnosis (false positive)

Pattern 2Cribriform/largegrowth pattern

Pattern 1Small glandulargrowth pattern

Pattern 3Fused gland/solidgrowth pattern

Mimics of Prostate Cancer

Pattern 1-Small gland Pattern 1-Small gland mimicsmimics

Seminal Seminal vesicle/ejaculatory duct vesicle/ejaculatory duct epitheliumepithelium

Cowper’s glandsCowper’s glands

Verumontenum Verumontenum hyperplasiahyperplasia

Crowding of small Crowding of small glandsglands

Mucinous metaplasiaMucinous metaplasia

Mesonephric gland Mesonephric gland hyperplasiahyperplasia

Post atrophic Post atrophic hyperplasia/atrophyhyperplasia/atrophy

Partial atrophyPartial atrophy

AdenosisAdenosis

Radiation atypiaRadiation atypia

Nephrogenic adenomaNephrogenic adenoma

Basal cell hyperplasiaBasal cell hyperplasia

PA: Among the most common reasons PA: Among the most common reasons for second opinionfor second opinion

Herawi M et al, AJSP, 2005

Partial atrophy (PA) - BackgroundPartial atrophy (PA) - Background

Experts have utiized various terms to Experts have utiized various terms to describe partial atrophydescribe partial atrophy

Some have used the term post atrophic Some have used the term post atrophic hyperplasia (PAH) to describe similar lesionshyperplasia (PAH) to describe similar lesions(Amin MB et al, 1999, Srigley JR et al, 2004)(Amin MB et al, 1999, Srigley JR et al, 2004)

Recently PA and PAH recognized as a Recently PA and PAH recognized as a distinct types of focal atrophy in the Working distinct types of focal atrophy in the Working Group Classification of Focal Prostate Group Classification of Focal Prostate Atrophy Lesions Atrophy Lesions (De Marzo et al, 2006)(De Marzo et al, 2006)

Partial atrophy - SignificancePartial atrophy - Significance

Potential for confusion with prostatic Potential for confusion with prostatic adenocarcinoma (PCa)adenocarcinoma (PCa)– Among the most common reasons for second Among the most common reasons for second

opinion in a consultation practice opinion in a consultation practice (Herawi et al, (Herawi et al, 2005)2005)

– Potential immunohistochemical (basal cell Potential immunohistochemical (basal cell markers and P504S (monoclonal antibody to markers and P504S (monoclonal antibody to AMACR)) overlap with PCaAMACR)) overlap with PCa

Association with inflammation and proliferation Association with inflammation and proliferation found in certain forms of atrophy such as post found in certain forms of atrophy such as post atrophic hyperplasia atrophic hyperplasia (Ruska et al, 1998; De Marzo et al, (Ruska et al, 1998; De Marzo et al, 1999; Shah R et al, 2001)1999; Shah R et al, 2001)

Architectural indicesArchitectural indices– Gland sizeGland size– Gland shapeGland shape– CircumscriptionCircumscription– Stromal characteristicsStromal characteristics– Associated completely Associated completely

atrophic glands within atrophic glands within the focusthe focus

– Luminal secretionsLuminal secretions– InflammationInflammation

Cytological indicesCytological indices– Character of Character of

cytoplasmcytoplasm– Nuclear size in relation Nuclear size in relation

to benign glandsto benign glands– Micronucleoli (visible Micronucleoli (visible

only at 40x) and only at 40x) and macronucleoli (visible macronucleoli (visible easily at 10X)easily at 10X)

AJSP, 32(1), 2008

Basal cell marker “cocktail”(34Basal cell marker “cocktail”(34ββE12 + p63)E12 + p63)– Completely positiveCompletely positive– Patchy positivePatchy positive– Completely negativeCompletely negative

P504S - Rabbit monoclonal antibody to AMACRP504S - Rabbit monoclonal antibody to AMACR (Zeta (Zeta corporation, Sierra Madre, CAcorporation, Sierra Madre, CA ))– NegativeNegative– WeakWeak– Moderate-to-strongModerate-to-strong(Expression evaluated in relation to benign glands)(Expression evaluated in relation to benign glands)

AJSP, 32(1), 2008

Study design - Proliferation statusStudy design - Proliferation status

Ki-67 (MIB-1 clone) immunohistochemistryKi-67 (MIB-1 clone) immunohistochemistry

Quantitative analysis by ChromaVision Quantitative analysis by ChromaVision ACISACIS– Measurement of stain intensity ofMeasurement of stain intensity of

PA foci compared with benign glands (range PA foci compared with benign glands (range 0-225, 0%-100%)0-225, 0%-100%)

– Manual delineation of fociManual delineation of foci

Results - Morphology (architectural Results - Morphology (architectural features)features)

Gland Shape

89%

3%

8%

Stellate & roundStellate onlyRound, poorly-formed

Growth Pattern

70%

30%

Circumscribed Disorganized

N=73 foci

Circumscribed focus with stellate – “star” shaped glands

Disorganized poorly formed round glands

Results - Morphology (architectural Results - Morphology (architectural features)features)

0 20 40 60 80 100

completely atrophic glands withinfocus

stromal sclerosis

inflammation

% CASES

FEA

TU

RE

S

Complete dark atrophic glands within the focus

Results - Morphology (cytologic Results - Morphology (cytologic features)features)

0 20 40 60 80 100

Clearcytoplasm

Micronucleoli

Macronucleoli

Nucleomegaly

% CASES

FEA

TU

RE

S

“Micro” nucleoli visible at high power

Other benign conditions known to Other benign conditions known to contain nucleoli:contain nucleoli:

> Basal cell hyperplasia> Basal cell hyperplasia

> Post atrophic hyperplasia> Post atrophic hyperplasia

> Adenosis> Adenosis

> Radiation atypia> Radiation atypia

> Benign glands associated with > Benign glands associated with inflammationinflammation

Clear cytoplasm similar to adjacent benign glands, placed laterally to Nuclei giving them partially atrophic look

Results: IHC – Basal cell markers Results: IHC – Basal cell markers cocktail 34cocktail 34ββE12 + p63E12 + p63

N=71

21%

73%

6%

Completely positive Patchy

Completely negative

Other lesions with Other lesions with patchy/negative basal cell patchy/negative basal cell

reactionsreactions

PINPIN

AdenosisAdenosis

Lack of basal cell staining in few atypical Lack of basal cell staining in few atypical glands is not necessarily diagnostic of glands is not necessarily diagnostic of cancercancer

Results: IHC – P504SResults: IHC – P504S

N=7290%

6% 4%

Negative Weak Moderate-strong

Comparison with published literatureComparison with published literature

AMACR resultsAMACR results– 79% (15/19 cases)79% (15/19 cases) (Herawi et al, 2005)(Herawi et al, 2005)

Series consisting of selected consultation cases Series consisting of selected consultation cases with AMACR staining performed at multiple with AMACR staining performed at multiple institutionsinstitutions

– 31% (38/122 foci)31% (38/122 foci) (Adley et al, 2006)(Adley et al, 2006)

Hospital based series, AMACR staining using the Hospital based series, AMACR staining using the triple antibody (P504S + CK 903+ p63)triple antibody (P504S + CK 903+ p63)

AMACR-specificity issuesAMACR-specificity issues

Study PIN(%) NA(%) Adenosis(%)Jiang et al Positive NS 27Jiang et al NS NS NSYang et al NS NS 17.5Beach et al 39 NS NSLuo et al Majority NS NSRubin et al Increased NS NSMagi-Galluzi et NS NS NSKunju et al 88 NS 14Zhou et al 100 NS NSSkinnider et al NS 35 NSGupta et al NS 58 NS

PIN= Prostatic intraepithelial neoplasia, NA= Nephrogenic adenomaNS= Not studied

Results - Basal cell markers and Results - Basal cell markers and P504S antibody as a panelP504S antibody as a panel

Profile of Antibody PanelProfile of Antibody Panel Number of foci Number of foci (%)(%)

N=70N=70

P504S(-)/basal cell markers(+)P504S(-)/basal cell markers(+) 58/70 58/70 (83%)(83%)

P504S(+)/basal cell markers(+)P504S(+)/basal cell markers(+) 7/70 7/70 (10%)(10%)

P504S(-)/basal cell markers(-)P504S(-)/basal cell markers(-) 5/70 5/70 (7%)(7%)

P504S(+)/basal cell markers(-)P504S(+)/basal cell markers(-) 0/70 0/70 (0%)(0%)

Results - Proliferation statusResults - Proliferation status

N=54 fociN=54 foci

Mean proliferative indices:Mean proliferative indices:– PA foci=5.5 (range 0-30)PA foci=5.5 (range 0-30)– Benign glands=5.6 (range 0-31)Benign glands=5.6 (range 0-31)– P=0.97P=0.97 (paired t-test) (paired t-test)

Summary - Features that potentially Summary - Features that potentially mimic prostate cancermimic prostate cancer

MorphologyMorphology– Disorganized growth patternDisorganized growth pattern– Small, round, poorly-formed glandsSmall, round, poorly-formed glands– Visible nucleoliVisible nucleoli

ImmunohistochemistryImmunohistochemistry– Very patchy/negative staining for basal cellsVery patchy/negative staining for basal cells– Possible AMACR positivityPossible AMACR positivity

Summary - Reliable morphologic Summary - Reliable morphologic features of PAfeatures of PA

Stellate/undulated gland luminaStellate/undulated gland lumina

Pale cytoplasm similar to adjacent benign glandsPale cytoplasm similar to adjacent benign glands

Presence of completely atrophic glands within Presence of completely atrophic glands within the focusthe focus

Lack of nuclear enlargement or macronucleoliLack of nuclear enlargement or macronucleoli

PAH PA

PAH = post atrophic hyperplasia, PA = partial atrophy

Morphological low-power comparison of PAH and PA

So where to draw a line between So where to draw a line between partial atrophy and atypia/cancer?partial atrophy and atypia/cancer?

Infiltrative glandsInfiltrative glands

Amphophilic cytoplasmAmphophilic cytoplasm

MacronucleoliMacronucleoli

Presence of blue mucinPresence of blue mucin

Lack of basal cell markers and/or AMACR Lack of basal cell markers and/or AMACR positivity with any of the above featurespositivity with any of the above features

Architectural/cytological Architectural/cytological features not specific but features not specific but

suggest the benign diagnosis:suggest the benign diagnosis:

ArchitectureLobular/circumscribed growth

Pseudo infiltrative appearance – “patch” like growth pattern

Benign glands as referenceSimilar cytoplasmic character

Benign gland

Cellular spindle cell stroma

BCHAdenosisSclerosing adenosis

Nuclei occupy full cell height

Complete atrophyBCH

“Random” cytological atypia

SVRadiation atypia

Random cytological atypia, smudgy nuclei, prominent nucleoli, cytoplasmic vacuolization

Radiation atypia

ConclusionsConclusions

A systemic approach using constellation of A systemic approach using constellation of architectural and cytological features necessary architectural and cytological features necessary to work up atypical small glandular proliferations to work up atypical small glandular proliferations

Diagnosis relies on constellation of features Diagnosis relies on constellation of features

Use markers to support your impression, use Use markers to support your impression, use them as a panelthem as a panel

An expert second opinion can help reduce An expert second opinion can help reduce atypia rate atypia rate

Thank You