Taking a PAP SMEAR

Cervical Cancer : Pap smear

George N Papanicolaou introduced cervical cytology in

clinical practice in 1940

In 1945, PAP smear was endorsed by American cancer

society as an effective method for prevention of cervical

cancer

Many countries now have National cervical screening

programs

Indian scenario Commonest cancer in women in India

Major cause of deaths in women due to cancer

Usually diagnosed at advanced stage

No National program

Uniformly low incidence of cervical screening in India (6% in rich & 4% in poor)

Histological Types 30

Squamous Cell Carcinoma : 80-95%

Adenocarcinoma : 5-20%

Other : Clear cell, sarcomas

Transformation zone Cervix develops from 2 embryonic sites

* from Mullerian duct - lined by columnar epithelium

* from urogenital plate - lined by stratified

squamous epithelium

Point at which columnar and squamous epithelium

meet is called as original squamo-columnar

junction

Transformation zone

Under influence of estrogen, original SCJ moves onto the portio.

Exposure of delicate columnar cells to vaginal environment leads to squamous metaplasia.

Transformation zone -

- Area of squamous metaplasia

- Area between original and new SCJ

Transformation zone

Transformation Zone -TZ Exposure of TZ to carcinogens begins the process of

intraepithelial neoplasia

While exact role of carcinogens in this process remains poorly

understood, it is clear that HPV and cigarette smoking can

cause dysplasia at the TZ

95% of cervical cancers develop in TZ

Important to take sample from TZ

Transformation Zone Transformation zone may not be viewed during

routine speculum examination

Why cervical screening is a feasible and useful strategy? Relative accessibility of cervix to take the smear

Long natural history of cervical carcinogenesis

Relative conservative treatment for premalignant lesions

Cost effectiveness3

PAP Smear

PAP smear sampling of cervix involves scraping of

cervical surface and a portion of non visualised

cervical canal using various sampling devices

Significance of Pap smear Detect precancerous & invasive cancer cervix cases in

early stages

Positive screeners can be selected for selective tests and management

With treatment, progression of disease is halted. Thus morbidity associated with advanced cancer decreases

Mortality reduces by 20-60 %.

Helps us to study natural history of disease.

Cervical Cancer : Pap smear

Early detection of pre-malignant lesions by Pap

smears prevent at least 70% of potential cervical

cancers.

Of the 30% who actually develop cervical cancer:

8% elude cytological detection

- imperfections in cytological technology

- biologic behavior of malignant lesions

22% represent women who develop cervical cancer because of

failure to regularly seek Pap smears => women whose cancers

could have been prevented with early detection and treatment.

How to take a Pap Smear ? Proper technique is very important

More problems are due to improper sampling than

screening

Not to be collected during menses

Avoid vaginal contraceptives, vaginal medications for at

least 48 hrs before taking smear

Abstinence for 24 hrs

Postpartum smear should be taken only after 6 - 8 weeks of

delivery

Patient in dorsal position

Good illumination is necessary

Cusco’s speculum is inserted to visualise & fix

the cervix

Inspection of cervix done & findings are noted

Ayres spatula is inserted first. It is placed at

cervical os so that longer end goes into cervical

canal and smaller end rests on ectocervix

How to take a Pap Smear ?

How to take a Pap Smear ? Spatula is rotated through 360 degrees

maintaining contact with ectocervix

Do not use too much force [bleeding /pain]

Do not use too less force [inadequate sample]

Sample is smeared evenly on the slide and fixed

immediately

Both sides of spatula are to be smeared

How to take a Pap Smear ? Endocervical sample is collected using an

endocervical brush

Insert the cytobrush into canal, so that last bristles

of brush are visible

Rotate the brush through 180 degrees. [more

rotations increase the chance of bleeding]

Sample is rolled on the slide and fixed.

Fixation of smear Fixation is done immediately with

fixative like 95% alcohol or cytofix

spray to avoid air drying

Spray should be kept at 10 inches, to

avoid destruction of cells by

propellent in the spray

Smear should monolayer for proper

penetration of cell surface by fixative

How to take a Pap Smear ?

Slide should be labeled properly with patients name,

identification no. and details

Detailed history and clinical examination findings are to be

mentioned

Patient details and clinical findings are to be maintained in a

register

Advice is given regarding further follow up and treatment

Systems for cervical cytology reporting George N Papanicolaou (1954)

5 classifications based on certainty of finding malignant cells

Descriptive system – WHO - (1968)

based on morphologic criteria – included mild, moderate, severe dysplasia and Ca In Situ

Richart – CIN –based on histologic diagnosis

Systems for cervical cytology reporting Bethesda system – TBS (1988)

National cancer institute revised in 1991 and 2001

Adequacy of smear must be determined before reporting

Smear is adequate when

- Patient identification

- adequate clinical history

Bethesda system Interpretable cellular cytology

not obscured by inflammation, debris, blood, drying

not scanty smear

Adequate sampling from transformation zone

presence of at least 2 clusters of well preserved

endocervical cells or metaplastic cells

Bethesda systemResults :

Within normal limits ( WNL )

Benign cellular changes - this term was removed and group was included in WNL in 2001

Reactive or Reparative changes – seen with atrophy, inflammation, surgery, radiation, IUCD, tampoons

Infections – trichomoniasis, fungal, bacterial, HSV.

Bethesda system - results Epithelial cells abnormalities

Squamous cells

• ASCUS

• ASCUS-H - suggestive of high grade lesion

• LSIL - changes associated with HPV, atypical changes, mild dysplasia/ CIN1

• HSIL – moderate to severe dysplasia / CIN2, 3 and Ca In Situ

• HSIL – where invasion cannot be ruled out

• Squamous cell carcinoma

Bethesda systemResults :

Glandular cells – AGUS (Endocervical, endometrial)

Adenocarcinoma

(endocervical, endometrial, extrauterine)

Other malignant neoplasms

Normal cervix-cytology Squamous cells

Exfoliated indivisual cells

Navicular in shape with abundant cytoplasm and small,

dark, round /oval, pyknotic nuclei

Glandular cells

Many times seen in clumps - linear or honeycombed

pattern.

Slightly larger and basal nuclei

Cervical cytology - Inflammation

Interpretation difficult due to inflammatory

background

Lot of neutrophils and blood can obscure

cellular details

Low grade lesions

High grade lesions

High grade squamous lesion

High grade glandular lesion

Abnormal Pap smear- HPV Peripherial condensation of cytoplasm -

wire looping effect

Koilocyte

PAP Descriptive CIN Bethesda

Class-1 negative negative WNL

Class 2

Inflammatory, squamous, koilocytic atypia

Reactive, reparatative changes, ASCUS, LSIL(HPV)

Class 3

Mild dysplasia

Moderate dysplasia

Severe dysplasia

CIN1

CIN2

CIN3

LSIL(HPV)

HSIL

HSIL

Class 4 Ca In Situ CIN3 HSIL

Class 5 Invasive Invasive Invasive

Single test will not detect cervical abnormality but with 3

negative tests there is less than 1% chance of cervical

abnormality

Conventional cytology has specificity of 98% and

sensitivity of 51%.

PAP smear

PAP Smears - Limitations Low sensitivity 51%

False negative rates are due to faulty sampling, improper

fixation or interpretation problems

Large group population & high risk group screening not

possible

No consensus regarding testing

Pap smear as screening method New guidelines

Target group - All women aged 18-70 yrs who have ever had sex Timing of Initial Screening -

Initial screening at age of 21 years or within 3 years of sexual activity

ACOG Guidelines-(Aug2003), American Cancer Society (Nov 2002) and U.S. Preventative Services Task Force (Jan 2003)

Pap smear - guidelines

Screening interval - yearly till the age of 30 then 3 yearly

When to End Screening

- After 70 yrs

- Post Hysterectomy

- done for benign lesions

- previous 3 normal PAP reports

- confirmed complete removal of cervical epithelium

Pap smear - guidelines In high risk group after treatment for CIN

every 3 monthly for 2 years every 6 monthly for 3yrs Yearly thereafter Women who had hysterectomy for CIN, it is necessary to do

vault smears In women who received vaccination against HPV, it is

necessary to continue screening

Liquid Based Cytology

To improve results of PAP newer techniques like liquid

based cytology are recommended

Cells are obtained with a broom, then the head is broken

off in to a vial containing preservative fluid

In the laboratory the sample is spun to remove obscuring

material

It gives clearer image, no cell clumps

It will assist in future automated reading

Several slides can be prepared from one smear

Chlamydia, HPV testing can be done at later date

Reduces the incidence of inadequate and repeat smears

Liquid Based Cytology

Cancer Cervix IS PREVENTABLE ,

IF Detected EARLY!!!!!!!!!

Thank You