Women's Health Pap Smear and Cervical
Dysplasia
Kimberly: Hello, my name is Dr. Kimberly Cheatham. Welcome to this video presentation on the pap
smear and cervical dysplasia. The objectives for this presentation are listed here. Since the pap smear
was first described by Dr. George Papanicolaou in the 1940s, its use has led to a significant decrease
in the occurrence of cervical cancer and related mortality. Those areas of the world that do not have
pap smear screening programs still have high rates of cervical cancer because most women who
develop cervical cancer have never been screened or have been screened inadequately. The sexuallytransmitted human papilloma virus, or HPV, is a necessary although not sufficient factor in the
development of squamous cervical cancer. Most women will become infected with HPV in their
lifetimes but do not develop significant cervical abnormalities because their immune systems are able
to suppress or eliminate the virus.
HPV is divided into 2 classes, oncogenic and non-oncogenic. Infection with an oncogenic type is
required for virtually all cervical cancers to develop. HPV type 16 has the highest carcinogenic
potential and accounts for approximately 55–60% of all cases of cervical cancer worldwide. HPV type
18 is the next most carcinogenic genotype and is responsible for 10-15% of cases of cervical cancer.
Some non-oncogenic types such as 6 and 11 are responsible for the occurrence of genital condyloma.
Only a small fraction of women infected with HPV will develop high-grade dysplasia or cervical
cancer. The current model of cervical carcinogenesis posits that HPV infection results in either
transient or persistent infection. Most HPV infection is transient and poses little risk of progression
because it is cleared by the immune system. Only a small fraction of infections are persistent. HPV
infection identified at 1 year and 2 years past initial detection strongly predict subsequent risk of highgrade dysplasia or cancer regardless of age.
Known cofactors that increase the likelihood of persistence of HPV and subsequent development of
cervical dysplasia and cancer include cigarette smoking, a compromised immune system, and HIV
infection. Other risk factors for acquisition of HPV and development of cervical dysplasia are listed
here. New technologies for cervical cancer screening continue to evolve as do recommendations for
managing the results. The most recent recommendations for cervical cancer screening in low-risk
women published by the American Society for Colposcopy and Cervical Pathology, or ASCCP, are
listed on the slide. Note that cytology or the pap smear alone is indicated for screening women
between 21 and 29 years of age. After 30 years of age, the recommended screening strategy is a pap
smear combined with testing for the presence of high-risk HPV.
A screening test such as the pap smear is most effective when it is performed properly. The technique
for pap smear screening is straight-forward, and the clinician benefits by understanding the histology
of the cervix. The cervix is the opening to the muscular organ of the uterus. The cervix contains 2 cell
types, columnar and squamous. Columnar cells are tall, thin cells that line the inside of the cervix, an
area referred to as the endocervix. Squamous are flat cells that are found on the outside or portio of
the cervix. This area of the cervix is also called the ectocervix. Where these 2 cell types meet on the
cervix is referred to as the squamocolumnar junction, abbreviated SCJ. The squamocolumnar junction
is the location of the cervix where most dysplasia occurs, so the pap smear should include cells from
this area.
When looking at the cervix with the naked eye, you can often visualize the SCJ. Columnar cells are
located in the middle of the cervix and are deep red. Squamous cells are on the outer surface of the
cervix and are a light pink. The SCJ occurs where these 2 cell types interface. This slide depicts the
normal process called metaplasia. As a woman ages, her SCJ, which originally started out on the face
of the cervix, will move in toward the cervical os. An older patient's SCJ may actually be inside the
endocervix and not visualized on exam. This apparent movement of the SCJ toward the cervical os
occurs when columnar cells transform into squamous cells at the SCJ during a woman's lifetime. This
transformation is called metaplasia.
The field of cervical cells located between where a patient's original SCJ was as a young girl and
where her SCJ is located now as an adult is called the transformation zone because columnar cells
previously located in this area have transformed into squamous cells. When performing a pap smear,
the goal is to obtain cells from the SCJ and the transformation zone because this is where more
dysplasia occurs. Every woman's cervix appears different. A woman's cervix can also appear different
based on her hormone status. The SCJ is more easily identified in young women when it is still out on
the portio of the cervix and during pregnancy as the cervix naturally everts. Can you see the SCJ on
the cervix on the left? The cervix on the right is from an adolescent. Her SCJ is located far back on
the cervix.
Both liquid-based and conventional glass slide methods of cervical cytology collection are acceptable
for screening. The conventional pap smear entails collecting cells from the transformation zone on a
wooden or plastic spatula and collecting endocervical cells with a cytobrush and smearing these cells
carefully on a glass slide. A preservative is quickly sprayed on the slide, which is sent to the lab for
staining and reading by the cytopathologist. Contaminating blood, vaginal discharge, and lubricant
may interfere with specimen interpretation. During liquid-based pap testing, cells are collected from
the transformation zone of the cervix and the endocervical canal and transferred to a vial of liquid
preservative that is processed in the laboratory. Contamination is less likely to occur with this method.
This slide shows the difference between liquid-based pap smear collection after processing, the slide
on top, versus traditional pap smear collection after processing, the slide on the bottom. You can
imagine that the top slide is easier to read for the cytopathologist. However, both methods are
considered acceptable. This slide shows the categories of information you will receive on the pap
smear report sent from the laboratory. The 2001 Bethesda classification system is the standard of
terminology for reporting the results of cervical cytology in the United States.
The ASCCP publishes management algorithms for abnormal pap smear results. If you are responsible
for triaging abnormal pap smear results in the future, you can refer to these algorithms. The pap smear
is a screening test, not a diagnostic test. The purpose of the pap smear is to detect cervical
abnormalities before they have progressed to cervical cancer so the patient can be effectively treated.
Pap smear results range from normal to LGSIL, or low-grade squamous intraepithelial lesion, HGSIL,
or high-grade squamous intraepithelial lesion, and ASCUS, or atypical squamous cells of
undetermined significance. If a patient requires further evaluation of an abnormal pap smear based on
the ASCCP management guidelines, the diagnostic test is colposcopy.
Colposcopy is performed in the office by a women's health clinician. The patient is placed in the
lithotomy position with her feet in stirrups. The clinician uses a specialized microscope to visualize
the patient's cervix under magnification. Biopsies are taken of abnormal-appearing areas. Biopsies
taken during colposcopy are sent to the pathologist for evaluation. Possible biopsy results may be
reported as CIN 1, 2, or 3 … CIN stands for cervical intraepithelial neoplasia … or CIS, carcinoma in
situ. CIN 1 is considered low-grade dysplasia, and observation is usually recommended. CIN 2, 3, and
CIS are high-grade dysplastic lesions that typically require treatment unless the patient is pregnant.
Cancer may also be diagnosed on biopsy.
If treatment is recommended per the ASCCP guidelines, several options are available, including
ablation of the abnormal cells with freezing techniques or with laser, or diagnostic excisional
procedures which cut out the abnormal cells so they can be sent to the pathologist for further
examination. Excisional procedures include the LEEP, laser, and cold knife cone.
This slide shows the equipment used for cryotherapy or freezing of the cervix, a type of ablative
treatment for cervical dysplasia. Liquid nitrogen flows through tubing with a metal tip that is applied
to the cervix to create an ice ball. A whitish frozen area on the cervix can be seen in the picture on the
lower right. Laser can be used to burn away abnormal cells or to cut out cells to send to the
pathologist for examination.
"LEEP" stands for loop electrosurgical excision procedure, L-E-E-P. A wire loop running a current of
electricity is connected to a plastic handle for the clinician to use. Abnormal cells of the cervix are cut
out and sent to the pathologist to ensure all margins are clear of disease. This is usually performed in
the clinician's office. A cold knife conization is performed with a scalpel in the operating room. A
cone-shaped piece of abnormal cervical tissue is cut out with a knife and sent for examination. The
procedures that remove tissue, laser, LEEP, and cold knife conization, have a small risk of weakening
the cervix, which could lead to pre-term birth in future pregnancies. This risk should be discussed
with patients who desire future child-bearing.
Are there any strategies we can use to prevent the transmission of HPV? There are 2 vaccines
available against HPV. The first vaccine is Gardasil, which protects against strains 6 and 11 that cause
90% of genital warts and strains 16 and 18 that cause 75% of cervical cancers. It is approved for
males and females ages 9–26 years. The second vaccine is Cervarix, which protects against strains 16
and 18 and is approved for females ages 10–25 years. These vaccines are only effective when
administered before a patient is exposed to these strains of HPV. That's why it's recommended to
vaccinate adolescents before they become sexually active. This concludes this video presentation on
the pap smear and cervical dysplasia.
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After reading the materials and viewing the video for this lesson, please respond to the following questions:
What are your thoughts about recommending the HPV vaccination?
Which age groups would you target? Why?