CYT 2113 Cytology I

Lesson 7:

Introduction to Pap Smear Test

Pap Smear

An examination under the microscope of cells

scraped from the tip of the cervix

(Cervix the lower part of the uterus that

opens at the top of vagina)opens at the top of vagina)

Done as part of a gynecological exam

How Pap Smear Test is Performed

The patient will lie and position pelvis for

examination

The health care provider will insert speculum

into vagina and open it slightly to see inside

the vaginal canalthe vaginal canal

A cotton swab is sometimes used to clear away

mucus that might interfere with an optimal

sample

A sample of cells is taken from the outside and

just inside the opening of the cervix (cervical

canal) by gently scrapping the outside of the

cervix with a wooden or plastic spatula, then cervix with a wooden or plastic spatula, then

inserting a small brush into the canal

The cells are placed on a glass slide, or put in a

bottle containing a preservative and then sent

to the lab for examination

The cells are examined under a microscope in

order to look for pre-malignant or malignant order to look for pre-malignant or malignant

changes

Pap Smear

Pap Smears

Conventional smears are often obtained using

the combination of a spatula and brush

The spatula is used first

Although a wooden or plastic spatula is Although a wooden or plastic spatula is

acceptable, the plastic spatula is

recommended because wooden fibers trap

diagnostic material

The spatula is rotated 360 degrees

The sample can be smeared on one half of a

slide and spray fixed (the other half should be

covered to avoid coating it with fixative before

the endocervical sample is applied)the endocervical sample is applied)

Alternatively, one may set aside the spatula

sample momentarily while the endocervical

brush sample is obtained

After the brush is inserted in the endocervical

canal, some bristles should still be visible

If inserted too far, there may be inadvertent

sampling of the lower uterine segment (LUS), sampling of the lower uterine segment (LUS),

which causes diagnostic difficulties because its

epithelium resembles a high-grade squamous

intraepithelial lesion (HSIL) and

adenocarcinoma in situ (AIS)

The brush should be rotated gently only one

quarter turn

A larger rotation is unnecessary because the

circumferential bristles are in contact with the

entire surface the moment the brush is

insertedinserted

The spatula sample, if not already applied and

fixed, should be applied to the slide, then the

brush sample rolled over the slide, followed

by immediate fixation

The two samples can be placed in quick

succession on two separate halves of the slide,

or the endocervical sample can be rolled

directly over the spatula sample, both directly over the spatula sample, both

covering the entire slide

Immediate fixation (within seconds) is critical

to prevent air-drying artifact, which distorts

the cells and hinders interpretation

The broomlike brush (broom) has a flat

array of plastic strips contoured to conform to

the cervix, with longer strips in the middle

This design allows simultaneous sampling of This design allows simultaneous sampling of

the endocervix and ectocervix

The long middle strips are inserted into the os

until the shorter outer strips bend against the

ectocervix

The broomlike brush

The broom is rotated three to five times

To transfer the material, each side of the

broom is stroked once across the slide in a

painting motionpainting motion

The cotton swab moistened with saline is no

longer recommended because its fiber trap

cells, reducing the efficiency of cell transfer

onto slides

Cervex brush Cytobrush

Spatula

There are two options for smear fixation

Coating fixatives contain alcohol and

polyethylene glycol and applied by pump

sprays, by droppers from dropper bottles, or sprays, by droppers from dropper bottles, or

by pouring from an individual envelope

included as part of a slide preparation kit

Alternatively, the smear can be immersed

directly into a container filled with 95%

ethanol

Samples for liquid-based cytology (LBC) are

obtained as described except that, instead of

smearing the cells on a slide, the collection

device is rinsed in a vial containing liquid device is rinsed in a vial containing liquid

fixative

How to Prepare for the Test

Tell the health care provider if you:

Are taking any medications or birth control pills

Have had an abnormal Pap smear

Might be pregnant

Within 24 hours of the test, avoid:

Douching

Having intercourse

Taking a tub bath

Using tampons

Avoid scheduling Pap smear while

menstruating because blood and cells from

the uterus may affect the accuracy of the Pap

smearsmear

Empty the bladder just before the test

Pap Smear

A simple, quick and relatively painless screening

test

Specificity (its ability to avoid classifying a normal

smear as abnormal) is very good but not perfectsmear as abnormal) is very good but not perfect

Sensitivity (its ability to detect every single

abnormality) is good but also not perfect

Some false negative results (in which

abnormalities are present but not detected by

the test) will occur

Thus, a few women develop cervical cancer

despite having regular Pap screening

In the vast majority of cases, a Pap test does

identify minor cellular abnormalities before they identify minor cellular abnormalities before they

have had a chance to become malignant and at a

point when the condition is most easily treatable

The Pap smear is not intended to detect other

forms of cancer such as those of the ovary, vagina

or uterus

Cancer of these organs may be discovered

during the course of the gynecologic (pelvic)

exam, which usually is done at the same time

as the Pap smearas the Pap smear

Why the Test is Performed

The Pap smear can detect cancerous or

precancerous conditions of the cervix

Most invasive cancers of the cervix can be

detected early if women have Pap tests and detected early if women have Pap tests and

pelvic examinations

Screening should start within 3 years after first

having vaginal intercourse or by age 21

After the first test:

Woman should have a Pap smear every 2

years to check for cervical cancer

If the woman is over age 30 or the Pap smears

have been negative for 3 times in a row, the

doctor may recommend Pap smear to be done doctor may recommend Pap smear to be done

every 3 years

If the woman or her sexual partner have other

new partners, then she should have a Pap

smear every 2 years

After age 65-70, most women can stop having

Pap smears as long as they have had three

negative tests within the past 10 years

If the woman has a new sexual partner after If the woman has a new sexual partner after

age 65, she should begin having Pap smear

screening

Who Should Have a Pap Smear

Women who have had a total hysterectomy

(uterus and cervix removed) and have not had

any previous history of cervical dysplasia

(abnormal cells), cervical cancer or any other kind (abnormal cells), cervical cancer or any other kind

of pelvic cancer, may not need to have Pap

smears

Pregnancy does not prevent a woman from

having a Pap smear

Pap smears can be safely done during pregnancy

The screening guidelines of American Cancer Society 2004:

When to start Pap smear testing 3 years after vaginal intercourse, no later than age 21

Frequency of Pap smear testing yearly with exceptions: every 2 years if liquid-based kit; every 2-3 years if three normal tests in a row in women 2-3 years if three normal tests in a row in women 30 years old

Age to stop having Pap smears total hysterectomy of benign disease 70 years old with at least three normal Pap smear results in the last 10 years

The screening guidelines of United States

Preventative Services Task Force 2003:

When to start Pap smear testing within 3

years of onset of sexual activity or age 21,

whichever comes firstwhichever comes first

Frequency of Pap smear testing at least

every 3 years (no evidence that every year is

better than every 3 years)

Age to stop having Pap smears

-recommend against doing Pap smears in

women older than 65 years of age, if adequate

screening with normal resultsscreening with normal results

- recommend against doing Pap smears in

women who have had a total hysterectomy for

benign disease

The screening guidelines of American College of Obstetrics and Gynecology:

When to start Pap smear testing 3 years after first sexual intercourse or age 21, whichever comes first

Frequency of Pap smear testing yearly until age 30 years. Beginning at age 30, if three normal annual Pap results, can do a Pap alone every 2-3 annual Pap results, can do a Pap alone every 2-3 years

Age to stop having Pap smears difficult to set an upper age limit- postmenopausal women screened within the prior 2-3 years have a very low risk of developing abnormal Pap smears

It has been seen that women who do not

participate in screening programs, and women

whose interval between smears is more than 3

years, are at highest risk for developing cervical

carcinoma

In Malaysia, all women who are, or who have

been sexually active, between the ages of 20 and been sexually active, between the ages of 20 and

65 years, are recommended to undergo Pap

smear testing

If the first two consecutive Pap results are

negative, screening every three years is

recommended.

Women with a history of cervical cancer, in

utero diethylstilbestrol (DES) exposure, and

who are immunocompromised (organ

transplantation, chemotherapy, chronic transplantation, chemotherapy, chronic

corticosteroid treatment, or positive for

human immunodeficiency virus) may benefit

from more frequent screening

Normal results

A normal value is negative, meaning there are no abnormal cells present

Abnormal results

Atypical cells of uncertain significance (ASCUS) these changes may be due to infection with HPV but may also mean there are precancerous but may also mean there are precancerous changes present

Low-grade dysplasia or high-grade dysplasia: this means precancer changes are likely to be present; the risk of cancer is greater if the result is high-grade dysplasia

Carcinoma in situ (CIS) this usually means the abnormal changes are likely to progress to cancer

Atypical squamous cells (ASC-H) this means Atypical squamous cells (ASC-H) this means abnormal changes have been found and may be high-grade squamous intraepithelial lesion

Atypical glandular cells (AGC) cell changes are seen that suggest precancer of the upper part of the cervical canal or inside the uterus

When a Pap smear shows abnormalities, further testing or follow-up is needed

The next step depends on the results of the Pap smear, previous history of Pap smears and risk factors for cervical cancer

This may include

- colposcopy-directed biopsy- colposcopy-directed biopsy

- An HPV test to check for the presence of the HPV virus types most likely to cause cancer

For minor cell changes, doctors usually recommend having a repeat Pap smear in 3-6 months

(colposcopy a procedure to closely examine

cervix, vagina and vulva for signs of disease)

Which women are at increased risk for having an

abnormal Pap smear?

A number of risk factors have been identified for

the development of cervical cancer and

precancerous changes in the cervix.

HPV: The principal risk factor is infection with the HPV: The principal risk factor is infection with the

human papillomavirus (HPV), although most

women with HPV infection do not get cervical

cancer

Smoking: Smoking increased the risk of cervical

cancer about two to four fold.

Weakened immune system: Women whose

immune systems are weakened by medications (for

example, those taken after an organ transplant)

also have a higher risk of precancerous changes in

the cervix. the cervix.

Medications: Women whose mothers took the

drug diethylstilbestrol (DES) during pregnancy also

are at increased risk.

Other risk factors: having multiple sexual partners

and becoming sexually active at a young age.

Strengths of Cytology Screening

The decades of experience in its use

High specificity

Its adaptability to computer-assisted reading

The lesions identified are easy to treat The lesions identified are easy to treat

Relatively low cost

Limitations of Cytology Screening

The test is difficult to comprehend in many

cultures

Invasive and potentially embarrassing

Trained personnel are required Trained personnel are required

Smear adequacy is not intrinsically obvious

It is necessary to recall women for further

tests if the results are not clearly negative

The test has only moderate sensitivity

Unable to distinguish progressive disease from

that destined to regress

It is impossible by screening to eliminate all

cervical cancer mortalitycervical cancer mortality

Essential Elements for a Successful

Cytology Screening Programme

Training of the relevant health care professionals,

including smear takers, smear readers

(cytotechnologists), cytopathologists,

colposcopists and programme managerscolposcopists and programme managers

An agreed decision on the priority age group to

be screened

Adequately taken and fixed smears

Efficient and high quality laboratory services, that

should preferably be centralized, quality control

of cytology reading

A means to rapidly transport smears to the

laboratory

A mechanism to inform the women screened

of the results of the test in an understandable of the results of the test in an understandable

form

A mechanism to ensure that women with an

abnormal test result attend for management

and treatment

An accepted definition of an abnormality to

be treated, i.e. high grade lesions

A mechanism to follow up treated women

A decision on the frequency of subsequent A decision on the frequency of subsequent

screens

A mechanism to invite women with negative

smears for subsequent smears

Elements that Interfere with the

development of Successful Cervical

Screening Programmes

Over-reliance on maternal and child health

services for screening, especially for defining

the target groupthe target group

Opportunistic (spontaneous) screening, often

focusing on frequent screening of low risk

women

Low compliance with screening of the target

group (evaluation by counting smears, rather

than counting women screened)

Setting too low a threshold for referral for Setting too low a threshold for referral for

colposcopy (over-treating non-progressive

disease)