PAP smear: named afterDr. George Papanicolaou (1883-1962)

Vaginal smears from guinea pigs (1917)

 Women (1920)

Hormonal cyclesPathological conditions (1928)

Cytologic screening for cervical cancer

Usefulness of pap smear in the screening programme for cancer cervix is shown by the following:

Long latent period of 10-15 years between CIN and invasive cancer allows adequate treatment of CIN and prevention of invasive cancer

Proved successful in reducing the incidence of invasive cancer by 80% and the mortality by 70%

When to screenStart within 3 years of onset of sexual activity or by age

of 21, whichever is first.

High risk factors for cervical dysplasia:

Early onset of sexual activity

Multiple sexual partners

Smoking habits

Oral contraceptives

HPV and HIV positive women

Screening frequency

Yearly until three consecutive normal pap smears, then

may decrease frequency to every 2-3 years

Annual screening for high-risk women is highly

recommend.

When to stop routine screening

Age 70 and “adequate recent screening”

Three consecutive negative pap smears

No abnormal pap smears in last 10 years

Hysterectomy for benign lesion

Original Squamous Epithelium

Vagina and outer ectocervix

4 cell layers

Well-glycogenated (pink) unless atrophic

Columnar Epithelium

Upper and middle endo-cervical canal

Single layer of columnar cells arranged in folds

Mucin producing (not true glands)

Squamous Metaplasia

Central ectocervix and lower endocervical canal

Replacement of columnar cells by squamous epithelium

Progressive and stimulated by

Acidic environment with onset of puberty

Estrogen causing eversion of endocervix

Original Squamo-columnar Junction

Placement determined between 18-20 weeks gestation

Most often found on ectocervix

Can be found in vagina or vaginal fornices

Less apparent over time with maturation of epithelium

“New” Squamo-columnar Junction

Border between squamous epithelium and columnar

epithelium

Found on ecto-cervix or in endo-cervical canal

Majority of cervical cancers and precursor lesions

arise in immature squamous metaplasia, i.e. the

leading edge of the squamo-columnar junction

Transformation Zone

Zone between original squamo-columnar junction

and the “new” squamo-columnar junction

Nabothian cysts visually identify the transformation

zone if present

Squamous Epithelium

Parabasal Cells

Intermediate Cells

Superficial Cells

Endocervix

Endocervical Cells

TechniqueVisualize entire cervix if possibleCarefully remove any obscuring

dischargeSample ectocervix first with spatulaSample endocervix with gentle

cytobrush rotationApply material uniformly to slideFix rapidly with spray or liquid fixative

Classification of Pap smearClass Reagen(WHO) Ruchart Bethesda

Class 1 negative negative Within normal

Class 2 inflammation ------ ASCUS

Class 3 Mild dysplasia CIN-l (HPV) LSIL (HPV)

Class 4 Mod dysplasiaSeve dysplasiaCarcinoma in situ

CIN-llCIN-lll

HSIL

Class 5 Invasive cancer Invasive cancer Invasive cancer

“Normal” Pap SmearNegative for intraepithelial lesion or

malignancyOther non-neoplastic findings

Reactive cellular changes Glandular cells status post

hysterectomyAtrophy

OtherEndometrial cells (women 40 yrs)

Normal smear

Epithelial Cell Abnormalities: Squamous

Atypical squamous cellsASC-US: undetermined significanceASC-H: cannot exclude HSIL

LSIL: low grade (CIN 1)HSIL: high grade (CIN 2 - 3)Squamous cell carcinoma

SIL and CIN

Various types of cervical lesions as seen on Pap smears:

CIN I.

Various types of cervical lesions as seen on Pap smears:

CIN Il

Various types of cervical lesions as seen on Pap smears:

CIN lll

Various types of cervical lesions as seen on Pap smears:

invasive squamous cell carcinoma.

Epithelial Cell Abnormalities: Glandular

Atypical glandular cells,specify site of origin,if possible

Atypical glandular cells - favor neoplastiaEndocervical adenocarcinoma in situAdenocarcinoma

Various types of cervical lesions as seen on Pap smears:

adenocarcinoma

AccuracySingle pap smear-diagnostic sensitivity 60%False negative results upto25% due to: too scanty,too thick,too bloody,poorly

stained smear misinterpretation by the cytologist• In the presence of infection repeat cytology

has to be done after the infection is controlled

Abnormal cytology is an indication of colposcopic evaluation and directed biopsy