Editing Pap test (section)

==Procedure==
[[File:Taking pap-smear 1.png|thumb|Sample collection for thin-prep-cytology from the cervix uteri of a 39-years-old multiparous woman (4 pregnancies). The cervical brush is visible just before entering the cervix uteri.]]According to the CDC, intercourse, douching, and the use of vaginal medicines or spermicidal foam should be avoided for 2 days before the test.<ref name="CDCscreen">{{cite web |title=Screening for Cervical Cancer |url=https://www.cdc.gov/cervical-cancer/screening/index.html |website=[[CDC]] |access-date=15 August 2024 |date=26 October 2023}}</ref> A number of studies have shown that using a small amount of water-based gel lubricant does not interfere with, obscure, or distort the Pap smear. Further, cytology is not affected, nor are some STD testing.<ref>{{cite journal |author=Wright, Jessica L. |year=2010 |title=The Effect of Using Water-based Gel Lubricant During a Speculum Exam On Pap Smear Results |url=http://commons.pacificu.edu/pa/190/ |url-status=dead |journal=School of Physician Assistant Studies |archive-url=https://web.archive.org/web/20130524100341/http://commons.pacificu.edu/pa/190/ |archive-date=24 May 2013 |access-date=4 February 2012}}</ref> The CDC states that Pap smears can be performed during [[Menstrual cycle|menstruation]].<ref name="CDCscreen" /> However, the NHS recommends against cervical screening during, or in the 2 days before and after, menstruation.<ref>{{Cite web |date=2023-07-14 |title=How to book cervical screening |url=https://www.nhs.uk/conditions/cervical-screening/how-to-book/ |access-date=2023-08-13 |website=[[NHS]] |language=en}}</ref> Pap smears can be performed during menstruation, especially if the physician is using a liquid-based test; however if bleeding is extremely heavy, endometrial cells can obscure cervical cells, and if this occurs the test may need to be repeated in 6 months.<ref>{{Cite book |last=Chan |first=Paul D. |url=http://archive.org/details/gynecologyobstet0000chan |title=Gynecology and obstetrics : new treatment guidelines |date=2006 |publisher=Laguna Hills, CA : Current Clinical Strategies Pub. |others=Internet Archive |isbn=978-1-929622-63-4}}</ref>

Pap smears begin with the insertion of a [[speculum (medical)|speculum]] into the vagina, which spreads the vagina open and allows access to the [[cervix]]. The health care provider then collects a sample of cells from the outer opening or external '''os''' of the cervix by scraping it with either a spatula or brush.<ref>{{Cite web |date=2022-10-13 |title=Cervical Cancer Screening - NCI |url=https://www.cancer.gov/types/cervical/screening |access-date=2023-08-09 |website=www.cancer.gov |language=en}}</ref>

Obtaining a Pap smear should not cause much pain,<ref>{{cite web |title=Excerpts from Changing Bodies, Changing Lives |url=http://www.ourbodiesourselves.org/publications/cbclex5b.asp |url-status=dead |archive-url=https://web.archive.org/web/20131218085453/http://www.ourbodiesourselves.org/publications/cbclex5b.asp |archive-date=2013-12-18 |access-date=2013-07-02 |publisher=Our Bodies Ourselves}}</ref> but may be uncomfortable.<ref>{{Cite web |title=Cervical screening: support for people who feel anxious about attending |url=https://www.gov.uk/government/publications/cervical-screening-support-for-people-who-find-it-hard-to-attend/cervical-screening-support-for-people-who-feel-anxious-about-attending |access-date=2023-08-09 |website=GOV.UK |language=en}}</ref> Conditions such as [[vaginismus]], [[vulvodynia]], or [[stenosis of uterine cervix|cervical stenosis]] can cause insertion of the speculum to be painful.<ref>{{cite web |title=All About Speculums: Finding What Works for You |url=https://www.ohsu.edu/womens-health/all-about-speculums-finding-what-works-you |website=www.ohsu.edu |access-date=15 August 2024 |language=en}}</ref><ref>{{cite journal |last1=Biggs |first1=Kirsty V. |last2=Soo Hoo |first2=San |last3=Kodampur |first3=Mallikarjun |title=Mechanical dilatation of the stenosed cervix under local anesthesia: A prospective case series |journal=Journal of Obstetrics and Gynaecology Research |date=April 2022 |volume=48 |issue=4 |pages=956–965 |doi=10.1111/jog.15179 |pmid=35132727 |language=en |issn=1341-8076|pmc=9303640 }}</ref>

In a conventional Pap smear, the cells are placed on a glass slide and taken to the [[laboratory]] to be checked for abnormalities.<ref>{{Cite web |title=Conventional Pap Test |url=https://www.slh.wisc.edu/clinical/cytology/analytical-services/conventional-pap-smear/ |access-date=2023-08-09 |website=Wisconsin State Laboratory of Hygiene |language=en-US}}</ref>

A plastic-fronded broom is sometimes used in place of the spatula or brush. The broom is not as good a collection device, since it is much less effective at collecting endocervical material than the spatula and brush.<ref>{{cite journal |vauthors=Martin-Hirsch P, Lilford R, Jarvis G, Kitchener HC | title = Efficacy of cervical-smear collection devices: a systematic review and meta-analysis | journal = Lancet | volume = 354 | issue = 9192 | pages = 1763–1770 | year = 1999 | pmid = 10577637 | doi = 10.1016/S0140-6736(99)02353-3 | s2cid = 22733963 }}</ref> The broom is used more frequently with the advent of [[liquid-based cytology]], although either type of collection device may be used with either type of cytology.

The sample is stained using the [[Papanicolaou stain|Papanicolaou technique]], in which [[tinctorial]] dyes and acids are selectively retained by cells. Unstained cells cannot be seen adequately with a light microscope. Papanicolaou chose stains that highlighted cytoplasmic keratinization, which actually has almost nothing to do with the nuclear features used to make diagnoses now.{{Citation needed|date=August 2024}}

A single smear has an area of 25 x 50&nbsp;mm and contains a few hundred thousand cells on average. Screening with light microscopy is first done on low (10x) power and then switched to higher (40x) power upon viewing suspicious findings. Cells are analyzed under high power for morphologic changes indicative of malignancy (including enlarged and irregularly shaped nucleus, an increase in nucleus to cytoplasm ratio, and more coarse and irregular chromatin). Approximately 1,000 fields of view are required on 10x power for screening of a single sample, which takes on average 5 to 10 minutes.<ref>{{Cite journal |last1=Bengtsson |first1=Ewert |last2=Malm |first2=Patrik |date=2014 |title=Screening for Cervical Cancer Using Automated Analysis of PAP-Smears |journal=Computational and Mathematical Methods in Medicine |volume=2014 |pages=842037 |doi=10.1155/2014/842037 |issn=1748-670X |pmc=3977449 |pmid=24772188|doi-access=free }}</ref>

In some cases, a computer system may prescreen the slides, indicating those that do not need examination by a person or highlighting areas for special attention. The sample is then usually screened by a specially trained and qualified cytotechnologist using a light [[microscope]]. The terminology for who screens the sample varies according to the country; in the [[UK]], the personnel are known as [[cytoscreener]]s, [[biomedical scientist]]s (BMS), advanced practitioners and [[pathologist]]s. The latter two take responsibility for reporting the abnormal sample, which may require further investigation.{{Citation needed|date=August 2024}}

===Automated analysis===
Since the early 2000s, there have been successful attempts to develop automated, computer image analysis systems for screening.<ref name="pmid15842055">{{cite journal |vauthors=Biscotti CV, Dawson AE, Dziura B, Galup L, Darragh T, Rahemtulla A, Wills-Frank L |title=Assisted primary screening using the automated ThinPrep Imaging System |journal=Am. J. Clin. Pathol. |volume=123 |issue=2 |pages=281–7 |year=2005 |pmid=15842055 |doi=10.1309/AGB1MJ9H5N43MEGX |doi-access=free }}</ref> Although, on the available evidence, automated cervical screening could not be recommended for implementation into a national screening program, an NHS Health technology appraisal in 2005 concluded that the "general case for automated image analysis ha(d) probably been made".<ref>{{cite journal |vauthors=Willis BH, Barton P, Pearmain P, Bryan S, Hyde C |title=Cervical screening programmes: can automation help? Evidence from systematic reviews, an economic analysis and a simulation modelling exercise applied to the UK |journal=Health Technol. Assess. |year=2005 |volume=9 |issue=13 |url=http://www.ncchta.org/fullmono/mon913.pdf }} {{Webarchive|url=https://web.archive.org/web/20080910144643/http://www.ncchta.org/fullmono/mon913.pdf|date=2008-09-10}}</ref> Automation may improve [[sensitivity (tests)|sensitivity]] and reduce unsatisfactory specimens.<ref name="pmid17604301">{{cite journal |vauthors=Davey E, d'Assuncao J, Irwig L, Macaskill P, Chan SF, Richards A, Farnsworth A | title = Accuracy of reading liquid based cytology slides using the ThinPrep Imager compared with conventional cytology: prospective study |journal=BMJ |volume=335 |issue=7609 |page=31 |year=2007 |pmid=17604301 |pmc=1910624 |doi=10.1136/bmj.39219.645475.55 }}</ref> Two systems have been approved by the FDA and function in high-volume reference laboratories, with human oversight.{{citation needed|reason=article|date=July 2007}}

===Types of screening===
{{for|other cervical screening tests and human papillomavirus testing|Cervical screening}}
* Conventional Pap—In a conventional Pap smear, samples are smeared directly onto a microscope slide after collection.
* Liquid-based cytology—The sample of (epithelial) cells is taken from the transitional zone, the squamocolumnar junction of the cervix, between the ectocervix and the endocervix. The cells taken are suspended in a bottle of preservative for transport to the laboratory, where they are analyzed using Pap stains.
[[File:Transformation zone types.png|thumb|240px|Transformation zone types, determining the Pap test location:<ref>International Federation for Cervical Pathology and Colposcopy (IFCPC) classification. References:<br>-{{cite web|url=https://www.rcpa.edu.au/Library/Practising-Pathology/Structured-Pathology-Reporting-of-Cancer/Docs/Transformation_zone|title=Transformation zone (TZ) and cervical excision types|website=[[:en:Royal College of Pathologists of Australasia|Royal College of Pathologists of Australasia]]}}<br>- {{cite journal|last1=Jordan|first1=J.|last2=Arbyn|first2=M.|last3=Martin-Hirsch|first3=P.|last4=Schenck|first4=U.|last5=Baldauf|first5=J-J.|last6=Da Silva|first6=D.|last7=Anttila|first7=A.|last8=Nieminen|first8=P.|last9=Prendiville|first9=W.|title=European guidelines for quality assurance in cervical cancer screening: recommendations for clinical management of abnormal cervical cytology, part 1|journal=Cytopathology|volume=19|issue=6|year=2008|pages=342–354|issn=0956-5507|doi=10.1111/j.1365-2303.2008.00623.x|pmid=19040546|s2cid=16462929|doi-access=free}}</ref><br>Type 1: Completely ectocervical.<br>Type 2: Endocervical component but fully visible.<br>Type 3: Endocervical component, not fully visible.]]
[[Image:Gray1167.svg|thumb|Cervix in relation to upper part of vagina and posterior portion of uterus.]]
[[File:Cytology of cervical squamous metaplasia.png|thumb|220px|Squamous metaplasia of the cervix, with typical features. Pap stain.]]

Pap tests commonly examine epithelial abnormalities, such as metaplasia, dysplasia, or borderline changes, all of which may be indicative of CIN. Nuclei will stain dark blue, squamous cells will stain green and keratinised cells will stain pink/ orange. Koilocytes may be observed where there is some dyskaryosis (of epithelium). The nucleus in koilocytes is typically irregular, indicating possible cause for concern; requiring further confirmatory screens and tests.

In addition, human papillomavirus (HPV) test may be performed either as indicated for abnormal Pap results, or in some cases, dual testing is done, where both a Pap smear and an HPV test are done at the same time (also called Pap co-testing).<ref>{{Cite journal |last1=Zhang |first1=Salina |last2=McNamara |first2=Megan |last3=Batur |first3=Pelin |date=June 2018 |title=Cervical Cancer Screening: What's New? Updates for the Busy Clinician |url=https://linkinghub.elsevier.com/retrieve/pii/S0002934318300950 |journal=The American Journal of Medicine |language=en |volume=131 |issue=6 |pages=702.e1–702.e5 |doi=10.1016/j.amjmed.2018.01.020|pmid=29408216 |s2cid=46780821 |url-access=subscription }}</ref>

===Practical aspects===
The endocervix may be partially sampled with the device used to obtain the ectocervical sample, but due to the anatomy of this area, consistent and reliable sampling cannot be guaranteed. Since abnormal endocervical cells may be sampled, those examining them are taught to recognize them.{{citation needed|date=November 2022}}

The endometrium is not directly sampled with the device used to sample the ectocervix. Cells may exfoliate onto the cervix and be collected from there, so as with endocervical cells, abnormal cells can be recognised if present but the Pap test should not be used as a screening tool for endometrial malignancy.{{citation needed|date=November 2022}}

In the United States, a Pap test itself costs $20 to $30, but the costs for Pap test visits can cost over $1,000, largely because additional tests are added that may or may not be necessary.<ref>{{cite journal | author = Bettigole C | title = The Thousand-Dollar Pap Smear | journal = New England Journal of Medicine | volume = 369 | issue = 16 | pages = 1486–1487 | year = 2013 | pmid = 24131176 | doi = 10.1056/NEJMp1307295 }}</ref>