Introduction to Colposcopy
The Papanicolaou smear (Pap smear) is a commonly used screening test
for dysplasia and cancer of the uterine cervix. Colposcopy is the diagnostic
test to evaluate patients with an abnormal cervical cytological
smear or abnormal-appearing cervix. It entails the use of a field microscope
to examine the cervix after acetic acid and Lougal's iodine are applied
to temporarily stain the cervix. The cervix and vagina are examined under
magnification, and all abnormal areas are identified. If the colposcopy
is satisfactory (the entire transformation zone is examined and the extent
of all lesions is seen), directed biopsies of all lesions and especially
the most severe lesions are performed. This leads to a tissue diagnosis
of the disease present. Click
here for a Transformation Zone picture.
Indications for colposcopy include: (1)
Lesions that are more likely to be missed or under-read by colposcopic
examination include endocervical lesions, extensive lesions that are difficult
to sample, and necrotic lesions. (2)
Papanicolaou smear consistent with dysplasia or cancer.
Papanicolaou smear with evidence of HPV infection (don't assume it is only
Papanicolaou smear with ASCUS or repeated ASCUS.
Papanicolaou smear with repeated inflammation.
Patients with a history of intrauterine diethylstilbestrol (DES) exposure.
NORMAL COLPOSCOPIC FINDINGS
Original Squamous Epithelium.
The original squamous
epithelium is a featureless, smooth, pink epithelium. There are no
features suggesting columnar epithelium such as gland openings or Nabothian
cysts. Epithelium is considered "always" squamous and was not transformed
from columnar to squamous.
The columnar epithelium is a single-cell layer, mucous producing, tall
epithelium that extends between the endometrium and the squamous epithelium.
Columnar epithelium appears red and irregular with stromal papillae and
clefts. With acetic acid application and magnification, columnar epithelium
has a grape-like or "sea-anemone" appearance. It is found in the endocervix,
surrounding the cervical OS, or (rarely) extending into the vagina.
Generally, a clinically visible line seen on the ectocervix or within
the distal canal (e.g., post-cryotherapy), which demarcates endocervical
tissue from squamous (or squamous metaplastic tissue). This is an anatomical
The physiologic, normal process whereby columnar epithelium matures
into squamous epithelium. Squamous metaplasia typically occupies part of
the transformation zone. At the squamocolumnar junction it appears as a
"ghost white" or white-blue film with the application of acetic acid. It
is usually sharply demarcated toward the cervical os and has very diffuse
Transformation Zone (Tz).
The geographic area between the original squamous epithelium (before puberty)
and the current squamocolumnar junction is the Transformation
Zone. It may contain gland openings, Nabothian cysts, and islands of
columnar epithelium surrounded by metaplastic squamous epithelium.
ABNORMAL COLPOSCOPIC FINDINGS
Atypical Transformation Zone.
A transformation zone with findings suggesting cervical dysplasia or neoplasia.
(Terms also can be applied to findings outside the transformation zone,
Acetowhite (AW). A transient, white-appearing epithelium following the
application of acetic acid. Areas of acetowhiteness correlate with higher
Punctation. A stippled appearance to capillaries seen end-on, often found
within acetowhite area appearing as fine to coarse red dots.
Mosaicism. An abnormal pattern of small blood vessels suggesting a confluence
of "tile" or "chickenwire" reddish borders.
Leukoplakia (hyperkeratosis). Typically an elevated, white plaque seen
prior to the application of acetic acid.
Abnormal blood vessels. Atypical, irregular vessels with abrupt courses
and patterns, often appearing as commas, corkscrews, or spaghetti. No definite
pattern is recognized, as with punctation or mosaicism. Suspect invasive
cancer. Complex pattern consisting of roughened, irregular cervical epithelium,
typically with abundant irregular vessel patterns. Blood vessels take bizzare
forms, which appear as commas, hair pins, spaghetti, or long, dilated,
unbranching vessels with irregular diameters.
OTHER COLPOSCOPIC FINDINGS
Cervicitis may cause abnormal Pap smears and make colposcopic assessment
more difficult. Many authorities recommend treatment before biopsy when
a STD is strongly suspected.
Traumatic erosions are most commonly caused by speculum insertion and over
vigerous Pap smears but can also result from such irritants as tampons,
diaphrams, and intercourse.
Atrophic vaginal or cervical epithelium may also cause abnormal Papancolaou
smears. Colposcopists will often prescribe estrogen for 2 to 4 weeks before
a colposcopy in order to "normalize" the epithelium before the examination.
This is generally felt to be safe even if dysplasia or cancer is present
because the duration of therapy is short and these lesions do not express
any more estrogen receptors than a normal cervix. (3)
cysts are normal. They are areas of mucus producing epithelium that
are "roofed over" with squamous epitelium. They do not require any treatment.
They provide markers for the transformation zone since they are in squamous
areas but are remnants of columnar epithelium.
The practice of colposcopy assumes that the worst parts of the worst lesions
will be biopsied. This requires that the borders of all lesions be entirely
seen. The entire transformation zone, including all the squamocolumnar
junction, also must be visualized in order for a colposcopy to be considered
adequate. Inadequate colposcopy with cytologic evidence of dysplasia or
extensive canal disease frequently requires cervical cone biopsy for work-up.
If the entire squamocolumnar junction or the limits of all lesions cannot
be completely visualized, a diagnostic conization with a cold knife cone,
laser cone, or LEEP conization is necessary. (4)
Carefully note the shape, position, and findings of all lesions in order
to draw a picture of the lesions and biopsy sites. Classically, the following
parameters are used to grade severity of lesions: (5)
Less Severe > > More Severe
Atypical vessels usually indicate severe dysplasia or cancer. Acetowhite
areas that have sharp geographic borders and a dimension of thickness or
roughness are likely to be histologically more severe. Furthermore, all
other things being equal, the presence of vessel atypia in any lesion implies
more severe dysplasia. (5, 6)
Mild acetowhite epithelium > Intensely acetowhite
No blood vessel pattern > Punctation > Mosaic
Diffuse vague borders > Sharp demarcated borders
Follows normal contours of the cervix > "humped up"
Normal iodine reaction (dark) > Iodine-negative epithelium (yellow)
Leukoplakia - usually a very good (condylomata) or a very bad sign (SCC)
A more formal system of assessing the severity of cervical dysplasia
is the Reid Colposcopic Index. (5, 6) It uses a point system to grade the
lesion margins, color, blood vessel pattern, and strong iodine staining
characteristics. It is more objective but not universally accepted as better
to classic subjective grading.
ECC and Biopsy
Apply topical 20% benzocaine (Hurricane Solution) to decrease pain. It
is effective in 30 to 45 seconds. Perform an Endocervical Curettage (ECC)
before taking any biopsies unless the resultant blood would make biopsy
difficult. Use a Kevourkian curette (preferably without a basket) and scrape
the canal, 360 degrees, twice. The sample appears as a coagulum of mucus,
blood, and small tissue fragments. Use ring forceps or a cytobrush to gently
retrieve the sample. Submit on paper and label "ECC." Do not do an ECC
on pregnant patients.
Next, perform cervical biopsy. Biopsy posterior areas first to avoid blood
dripping over future biopsy sites. The cervix can be manipulated with a
Q-tip or hook if necessary to provide an adequate angle for biopsy.
Align the forcep radially from the os so that the fixed jaw of the forcep
is placed on the most posterior part of the site. The jaws should be centered
over the area to be biopsied. Biopsies should be approximately 3 mm deep
and should include all areas with vessel atypism. It is not necessary to
include normal margins with biopsy samples. If bleeding is profuse from
a particular site and more biopsies are needed, apply a Q-tip to the area
and proceed with the next biopsy.
Do not apply Monsel's solution until all biopsies are completed. Apply
pressure first and Monsel's solution if needed to bleeding sites. The Monsel's
should be as thick as toothpaste to be most effective. Swab out the excess
Monsel+blood debris, that appears as a nasty black substance which eventually
will pass and may cause alarm (and potential late night phone calls).
Follow-up is usually in 2 to 3 weeks to discuss pathology results and plan
treatment if necessary. With the high regression rate of CIN 1, patients
can be followed with serial colposcopy if adequate follow-up can be assured.
(4) CIN 2 and 3 are usually treated.
Be concerned if a significant discrepancy is found between the colposcopic
impression, Pap cytology, and biopsy histology. Be especially concerned
if the biopsy reports are significantly less than Pap cytology. For instance,
a Pap smear indicating carcinoma-in-situ and biopsies of only mild dysplasia
could signify that the worst area was not biopsied. In general, a difference
of one grade (i.e., Pap = CIN 2 and biopsy = CIN 3) is common and acceptable.
Do not freeze any cervix until you have adequately and sufficiently explained
any discrepancy between histology and cytology. If the discrepancy cannot
be explained, conization is indicated. (2) Repeating colposcopy is forgivable,
even in the hands of the best. Freezing invasive cancer is not.
Cone biopsy (cold cone, laser, or LEEP cone) is indicated if the endocervical
curettage sample reveals dysplasia. It is a sin to freeze the cervix with
disease in the canal. "Positive" ECC's are sometimes a result of contamination
with dysplastic lesions at the verge of the os. Nonetheless, do not assume
Know your limitations! Never be afraid to call in help with an uncertain
lesion or result.
Candidates for outpatient cervical cryotherapy are patients with smaller
lesions that do not enter the cervical os. Large lesions (over 1" in diameter,
more than 1/2" from the os, or involving more than two cervical quadrants),
even if they are only mild dysplasia, may be more appropriate loop or laser
therapy candidates than a small focal severe dysplasia that may respond
to ambulatory cryotherapy very well. (4) Large lesions, lesions that enter
the cervical os, or CIN 3 / CIS lesions are most appropiately treated with
LEEP or laser therapy.
Follow-up after treatment is in 4- to 6-month intervals for 2 years, with
colposcopy or colposcopy intersperced with Pap smears. Recurrence is most
common in the first 2 years after therapy. Recurrences are most common
in the os and on the outside margins. A positive margin on a LEEP specimin
requires colposcopic follow-up.
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practice residencies. J Fam Pract 1990; 31:171-8.
2. McCord ML, Stovall TG, Summitt RL, Ling FW. Discrepancy of cervical
cytology and colposcopic biopsy: Is cervical conization necessary? Obstet
Gynecol 1991; 77:715-9.
3. Sadan O, Frohlich RP, Driscoll JA, Apostoleris A, Savage N, Zakust
H. Is it safe to prescribe hormonal contraception and replacement therapy
to patients with premalignant and malignant uterine cervices? Gynec Oncol
4. Brotzman GL, Apgar BS. Cervical intraepithelial neoplasia: Current
management options. J Fam Pract 1994; 39:271-8.
5. Reid R, Campion MJ. HPV-associated lesions of the cervix: Biology
and colposcopic features. Clin Obstet Gynecol 1989; 32:157-79.
6. Reid R, Scalzi P. Genital warts and cervical cancer. VII. An improved
colposcopic index for differentiating benign papillomaviral infections
from high-grade cervical intraepithelial neoplasia. Am J Obstet Gynecol
7. Stafl A, Wilbanks GD. An international terminology of colposcopy:
Report of the nomenclature committee of the International Federation of
Cervical Pathology and Colposcopy. Obstet Gynecol 1991; 77:313-4.