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PAP smear-what to do if no transformation zone present

May 10, 2011

When the PAP smear is satisfactory for evaluation? What are the new guidelines if the transformation zone is not presented? Here it is a nice website to start with Hologic. I had a 49 years old patient without risk factors and past abnormal smear. Her PAP smear came back specimen satisfactory for evaluation, but not transformation zone. I did check uptodate and the new guidelines for speciments w/o transformation zone are:

Satisfactory for evaluation — Criteria for “satisfactory for evaluation” are:

·Squamous cellularity — conventional Pap smears must have at least 8000 to 12,000 well-visualized squamous cells; liquid-based preparations must have a minimum of 5000 well-visualized squamous cells

·Labeled specimen

Cellularity may be diminished in women who have been treated with pelvic radiation. This information should be included in the cytology requisition, and the reporting of results will depend on the clinical context and the ability of the laboratory to evaluate the specimen [7].

Cervical cytology specimens that are designated “satisfactory for evaluation” may, in addition, be described using what are referred to as “quality indicators”. Quality indicators include scant cellularity, partially obscuring blood or inflammation, poor fixation, thickly smeared slides, and absence of endocervical or transformation zone (EC/TZ) component [8].

Endocervical cell/transformation zone component — A notation is made regarding the presence or absence of an endocervical cell/transformation zone (EC/TZ) component, but these cells are not required for a cervical cytology test to be classified as satisfactory according to Bethesda 2001 criteria [4]. The criteria for an EC/TZ component is at least 10 well-preserved endocervical or squamous metaplastic cells; clusters of cells are not required as they were in Bethesda guidelines prior to 2001.

The presence of metaplastic and endocervical cells gives an indication of the sampling of the transformation zone of the cervix (junction of squamous and glandular cells, generally at the external cervical os). The transformation zone is the area at greatest risk for neoplasia [9]. The EC/TZ component is more likely to be absent in adolescents and women older than 30 years, particularly postmenopausal women [10,11].

The clinical significance for cervical cancer screening of the absence of the EC/TZ component in a cervical cytology specimen is controversial [7,10,12-15]. In specimens that lack endocervical cells, cytologic evaluation yields a lower rate of cellular abnormalities [10,12,14]. This was best illustrated in a prospective study of over 4000 women in whom cervical cytology specimens without an EC/TZ component were found to have a significantly lower detection rate of epithelial abnormalities than specimens with an EC/TZ component (11 versus 18 percent) [10].

Since cytologic abnormalities are the indication for further evaluation with colposcopy and cervical biopsy, this raises the question of whether a histologic diagnosis of cervical intraepithelial neoplasia (CIN) or cervical cancer will be missed in women in whom a Pap test lacks an EC/TZ component. However, there appears to be no increase in the development of high-grade CIN or cancer in these women [10,15-17].

When cervical cytology is repeated in women who have had a Pap test without an EC/TZ component, data suggest that there is no increase in cellular abnormalities compared with other women [10,18]. This was illustrated in the prospective study of 4000 women described in a preceding paragraph, repeat cytology performed after a median of 60 days (range 13 to 991 days) showed no significant difference in the rate of epithelial abnormalities in women without versus with an EC/TZ component on the initial specimen [10].

In addition, longitudinal studies (six months to eight years of follow-up) of 40,000 to 60,000 women with a Pap test that was reported as negative for epithelial abnormalities but lacked an EC/TZ component found no increase in histologic diagnoses of high-grade CIN or cervical cancer compared with women with an EC/TZ component (in one study, for high-grade CIN, 0.6 to 2.6 versus 2.9 per 1000 years of follow-up [15]; in the other study, for high-grade CIN, 6.2 versus 6.1 per 1000 and for cervical cancer, 0.53 versus 0.54 per 1000 [17]).

On the other hand, the proportion of endocervical adenocarcinoma among all cervical carcinomas is increasing. Since these cancers most commonly arise in the glandular cells of the endocervix, it is plausible that the detection of such cancers may be reduced in specimens that lack an EC/TZ component [19]. However, glandular abnormalities are less common than squamous abnormalities and there are few data to support or refute this concern [15,20].

The advent of testing for HPV strains that are associated with a high risk of cervical neoplasia (table 2) has not clarified this issue. A potentially clinically important subgroup is women with a negative cervical cytology specimen that lacks an EC/TZ component who have negative cytology and a positive HPV test. It is unknown whether abnormal endocervical cells may have been missed in these women [7]. It appears that women with a negative Pap test and positive HPV appear to have an increased risk for subsequent cervical neoplasia; however, studies of this issue do not report the rate of Paps without an EC/TZ component [21]. (See “Screening for cervical cancer”.)

For women with an inadequate EC/TZ component and a negative HPV test, the issue is whether the lack of these cells decreases the sensitivity of the HPV test. Two retrospective series from the same institution of over 26,000 negative cervical cytology specimens that were tested for high-risk HPV found no significant difference in the prevalence of HPV in specimens without or with an EC/TZ component (2.5 versus 2.2 percent) [11,22].

A task force of the American Society for Colposcopy and Cervical Pathology addressing the issue of cervical cytology specimens lacking an EC/TZ zone recommended that most women without an EC/TZ component be screened with a repeat Pap test in 12 months and not to wait longer for a repeat test, even for women who would otherwise be candidates for less frequent screening. (See “Screening for cervical cancer”.) [7]. However, repeat cervical cytology in six months was advised in the following situations:

·A previous cervical cytology test result of atypical squamous cells of undetermined significance (ASC-US) or worse without two subsequent negative cervical cytology tests or a subsequent negative HPV test

·A previous cervical cytology test with an unexplained glandular abnormality

·A positive test for a high risk HPV strain within the previous 12 months (table 2)

·Inability to clearly visualize or sample the endocervical canal

·Similar obscuring factor in consecutive Pap tests

·Insufficient frequency of previous screening

I asked some of the senior residents and they advised me to repeat the PAP smear. However, I decided to speak to some of the experts in the field.  I spoke to a pathologist and OBGYN docs and both of them confirmed that the PAP smear can be repeated in 6 to 12 months. There is no need to be repeated now. If you repeat the test less than 6 months the insurance company will not pay the repeated test.

In addition to the above info a quick question (easy one) from hopkinsilc:

A 38-year-old HIV negative woman presents for gynecologic screening. She is married, monogamous, with two healthy children. Her Pap smear is reported as having ASCUS with high risk HPV subtypes. According to national guidelines, what management is recommended?

a). Refer for colposcopy now
b). Repeat Pap smear in 6 months
c). Repeat Pap smear in one year
d). Treat with metronidazole and then repeat the Pap smear

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5 Comments leave one →
  1. Anonymous permalink
    January 24, 2012 8:51 pm

    A blanket statement about whether or not insurance will pay for a repeat test is not appropriate. I have never had a problem getting insurance to pay for a repeated pap, if coded correctly. There is an ICD -9 code for just this situation. Don’t let this be a deterrant in repeating your pt’s pap if you think it is the appropriate screening.

    • January 24, 2012 9:42 pm

      Thank you so much for this comment. I totally agree with you. I am still in residency and don’t have much experience with the disease coding system. I assume that there is more then one way to skin a cat. However, regardless the insurance issue, if the pt has is in the low risk group, repeating the PAP in 6 months to 1 year is appropriate.

  2. RachelRae permalink
    May 22, 2012 11:25 pm

    She needs a colpo as she is high risk HPV +… Await colpo results then she may need cryo, LEEP, laser or just a repeat pap in 6 months.
    I was always taught, if high risk + you always do a colpo.. it doesn’t matter if pt is ASCUS, LSIL or HSIL.

  3. http://google.com permalink
    February 14, 2013 4:09 pm

    How did you actually acquire the suggestions to post ““PAP smear-what to do
    if no transformation zone present USMLEMD”?

    Thanks for your time -Christy

  4. February 27, 2013 4:01 pm

    Your blog post, “PAP smear-what to do if no transformation
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