Pathology Journal Reading Presented by Intern 曾德朋

Pathology Journal ReadingPathology Journal Reading

Presented by Intern 曾德朋

ObjectiveObjective

To identify the role of cytokeratins in distinguishing intraductal papilloma from papillary ductal carcinoma in situ

IntroductionIntroduction

Papillary breast tumors: Proliferated mammary epithelium projects into duct lumen

Intraductal papilloma Preinvasive papillary ductal carcinoma in situ (DCIS)

Sometimes difficult to distinguish: overlapping microscopic appearances

The need to separate them…The need to separate them…

Distinct biologic behaviorPapillary DCIS potentially progressing to invasive cancer

Surgical extirpation

Benign papillomasDischarged from clinical follow up

Cytokeratins (CK)Cytokeratins (CK)

Fundamental markers of epithelial differentiation

Cell type & differentiation status

Previous studies: CK5/CK6, 34BE12 and CK14 in distinguishing usual epithelial hyperplasia from atypical ductal hyperplasia (ADH) and DCIS

Presence of myoepithelial cellsPreserved in benign papillomas, scant in papillary DCIS

Muscle actin and 34BE12 (less specific)

In this study…In this study…

Detail the expression of three CK antibody preparation

CK5/6CK1434BE12 (recognizing CKs 1, 5, 10 and 14)

Aim of this study…Aim of this study…

determining their role (CKs) in differentiating the benign papilloma from malignant in situ papillary carcinoma

Scant literature that specifically addresses papillary lesions

previous work focusing on proliferative breast lesions as a generic group versus DCIS

Semiquantitative criteria of immunoscores to evaluate the CKs

Ascertain the findings by extrapolating to a separate group

Materials and MethodsMaterials and Methods

Patients and tumors50 excision biopsies of papillary breast lesions (25 intraductal papillomas and 25 papillary DCIS)

Department of Pathology, Singapore General Hospital, 2002~2003

Variously reported by 14 general surgical pathologists - initially

Diagnostic review and assignment to papilloma and papillary DCIS by Pathologist P.H.T

Results were all in concordance with initial diagnosis

Materials and Methods…Materials and Methods…

Cont…Intraductal papillomas (25 cases)

Age: mean 44.1 y/o (22-78 y/o)Epithelial hyperplasia of mild to florid degreeNo atypical ductal hyperplasia

Papillary DCIS (25 cases)Age: mean 57.4 y/o (35-78 y/o)No invasive elements present

Cont…43 Hong Kong cases

As to confirm the result with a separate distinct cohortInitial diagnosis: 10 general surgical pathologistsHistologically reviewed by pathologist G.M.TCases: age: mean 52.5 y/o

1993 ~ 2001Excision biopsies 36 casesCore biopsies 7 casesSubmitted for CK immunohistochemical staining at SGH, without prior discussion


Cont…Immunohistochemistry

Human tonsil, squamous cell carcinoma and prostate: positive controls for CK5/6, CK14, and 34BE12, respectively

Normal ducts and ductules in the breast tissues: internal control


Cont…Scoring of sections

Staining intensity: 0, no staining; 1+, weak; 2+, moderate; 3+, strong

Quantification of positivity (0%~100%)Estimate of the percentage of stained tumor cells in the lesion

Immunoscores: multiplying the staining intensity with percentage positivity (0~300)

Negative or low (0~50); Moderate (51~100); High (101~200); Very high (201~300)


Cont…Confocal microscopy

Statistical analysisTwo-tailed t test: differences in immunoreaction between the two sample groupsPositive predictive value: CK immunoscore of <50

Papillary DCISNegaive predictive value: CK immunoscore of >50

Papilloma

Reevaluate for cases with discrepancies


Results: Results: Cytokeratin expression in a normal breast ductuleCytokeratin expression in a normal breast ductule

ImmunoreactionsImmunoreactionsIntraductal Papillomas and Papillary DCIS (SGH cases)Intraductal Papillomas and Papillary DCIS (SGH cases)

CK5/CK6Papillomas

72% : moderate to high immunoscoresPapillary DCIS

All: low immunoscores with 10 being completely negativeCK14

Papillomas84% high to very high immunoscores16% moderate to low immunoscores

Papillary DCIS84% low immunoscores 16% moderate immunoscores

34BE12Papillomas

56% high to very high immunoscores44% low to moderate

Papillary DCIS80% low 20% moderate (1 case: high positivity)


t testStaining intensity, precetage positivity, immunoscores for each CK:

all three parameters showed significantly higher in papillomas than DCIS


CK5/CK6CK5/CK6

• CK5/CK6 expression in an intraductal papilloma (left panel) and

Papillary DCIS (right panel)

• About half of the tumor cells in the papilloma were stained, whereas

tumor cells in DCIS were nonreactive

CK14CK14

• CK14 expression in an intraductal papilloma (left panel) and


• More than half of the tumor cells in the papilloma were stained,

whereas tumor cells in DCIS were nonreactive

34BE1234BE12

• 34BE12 expression in an intraductal papilloma (left panel) and


• Approximately half of the papilloma tumor cells were stained,

some DCIS tumor cells were also decorated

Confocal microscopy of CKsConfocal microscopy of CKs

Results…Results…

Hong Kong casesImmunoscores objectively determined by PHT (SGH)

CK5/CK6 corroboratedPapilloma 89.3%Papillary DCIS 86.7%

CK14Papilloma 92.9%Papillary DCIS 86.7%

34BE12Papilloma 96.4%Papillary DCIS 33.3%

Discordant casesDiscordant cases

SGH and HK casesSGH and HK cases

Statistic values…Statistic values…

DiscussionDiscussion

CytoskeletonMicrotubules, microfilaments and intermediate filaments (CKs belong to one of 5 classes of intermediate filaments)

CKs: cytoplasmic scaffoldSustain mechanical and nonmechanical stressesParticipation in the response to stress, cell signaling and apoptosisTo date: 20 CKs (12: acidic type I; 8 neutral-basic type II)


Normal resting mammary glandEpithelium lining

Inner luminal epithelial (LE) cellsCKs 7, 8, 18, 19

Outer myoepithelial (ME) cellsCKs 5, 14, 17


Previous studiesMonoclonal antibodies specific against simple and/or basal type CKs

Benign and malignant intraepithelial proliferations of breastAtypical proliferationsInvasive breast carcinomas

No study compares the expression of basal-type CKs in papillary tumors


Our resultsCK14 stained a significantly larger percentage of tumor cells in papilloma

Breast epithelium of proliferating mammary gland

3 types of cells: immature precursor (CK5/CK6)intermediate (CK5/CK6, CK 8, 14, 18, 19), fully mature (CK14, 18, 19)

Intraductal papillomaLarger proportion of fully mature cells


34BE12Stained more DCIS tumor cells

Recognizes CK1, 10, 5, 14CK10 expressed in some LE cells in breast cancers (previous studies)


Results applied to a separate distinct cohort of HK cases, confirmation of

Benign papilloma diagnosis 89.3% (CK5/CK6) to 96.4% (34BE12)

Discordant cases: small or core biopsyADH case: necessity for microscopic reevaluation

Papillary DCIS (result at odds)Core biopsyInvasive component (detect LE as well)

Not as reliable or sensitive as the other 2 CKsApocrine nature

In summaryIn summary

The three CKs can serve as helpful adjunctive markers Particularly combination of CK5/CK6 and CK1434BE12: low detection rate

Especially in delineation of papillary DCIS

Use of CKs on small lesions, core biopsies, apocrine morphology, and associated invasive cancer need further evaluation

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Pathology Journal Reading Presented by Intern 曾德朋