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Editor: Charles J. Dunton Updated: 11/12/2023 10:28:14 PM


Colposcopy is a diagnostic procedure in which a lighted magnifying instrument called a colposcope is used to examine the cervix, vagina, and vulva. Hans Hinselmen of Germany first described colposcopy in 1925 as a screening tool for cervical cancer. The procedure is performed to evaluate patients with an abnormal Papanicolaou (Pap) test, those who test positive for high-risk human papillomavirus (HPV) DNA, or those with a suspicious appearing cervix, even if screening for dysplasia is negative. It may also be performed as a posttreatment follow-up of cervical intraepithelial neoplasia (CIN) and invasive carcinoma.

Although colposcopy is practiced by many clinicians (including advanced practice providers, primary care providers, gynecologists, gynecological oncologists, and others), standardization of the procedural process, necessary training, and continued development and maintenance of colposcopic skills are generally poor. It is also well-documented that colposcopy has significant interperformer variability and poor reliability. In 2017, the American Society for Colposcopy and Cervical Pathology (ASCCP) published colposcopy standards to address these and other concerns.[1] The standardization of terminology was established to simplify and ensure a comprehensive colposcopic exam was performed at every encounter.[2]

Anatomy and Physiology

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Anatomy and Physiology

The cells at the squamocolumnar junction (SCJ) of the endo- and ectocervix are susceptible to HPV infection and dysplastic change. The virus incorporates its DNA into the developing cell and turns off the tumor suppressor gene (p53 and RB) function, allowing cells to become dysplastic. This is a slow, gradual process with many developmental stages that can be identified before the dysplasia progresses to cervical cancer (>90% of which is caused by HPV).

Given the Pap as an adequate screening test for sampling these changing cells, the dysplastic process can be identified early and treated before progressing to cervical cancer. Dysplasia is not limited to the cervix; the vaginal and vulvar tissue are also susceptible to the HPV virus. Colposcopy of the cervix and vagina are essentially identical; however, because the vulval tissue has a delayed absorption of acetic acid, the procedure is slightly modified.


The indications for a colposcopy are risk-based. Women referred for colposcopy have various underlying risks for cervical precancer based on their cytological results, HPV testing (if it was performed), and sometimes a personal history of cervical dysplasia. Each can be triaged accordingly, but when colposcopy is indicated, it is used to diagnose the presence of dysplasia and its severity. 

Indications for colposcopy are as follows:

  • Evaluation of women with an abnormal Pap test
    • To localize the lesion
    • To map the extent of the lesion
    • To select the biopsy site or sites
  • Evaluation of women testing positive for high-risk HPV DNA
  • Evaluation of women with positive visual inspection with acetic acid test results
  • Evaluation of a suspicious appearing cervix with postcoital or postmenopausal bleeding, even if the Pap smear is negative
  • Unexplained abnormal lower genital tract bleeding
  • Persistent inflammatory or unsatisfactory cervical cytology despite appropriate treatment, especially with high-risk factors for carcinoma of the cervix
  • Evaluation of persistent abnormal vaginal discharge or pruritus vulvae
  • Identification and management of subclinical papillomavirus infection
  • History of in-utero diethylstilbestrol (DES) exposure
  • Conservative management of intraepithelial neoplasia
  • Identification and management of vaginal extension of cervical neoplasia
  • Posttreatment follow-up
    • After treatment of intraepithelial neoplasia and invasive carcinoma
    • Postradiation follow-up [3][4][5]

Not all Pap tests must be followed by colposcopy, though many are. Low-risk Pap tests (ie, low-grade squamous intraepithelial lesion [LSIL] or atypical squamous cells of undetermined significance [ASCUS] with negative HPV) are not as likely to have significant colposcopic findings, including severe dysplasia. Therefore, immediate colposcopy is not indicated, and the patient can follow up the following year with a repeat Pap test. However, if the Pap test remains abnormal with LSIL or ASCUS positive for HPV, a colposcopy is recommended.

Some Pap test findings are more closely associated with severe cervical dysplasia. These include high-grade squamous intraepithelial lesions (HSIL) and atypical squamous cells and cannot exclude high-grade intraepithelial lesions (ASC-H). When there is suspicion of high-grade lesions, a possibility exists that invasive cervical cancer could be present. Immediate colposcopy is recommended in patients with initial Pap test findings more closely correlated with severe cervical dysplasia.

Current guidelines for colposcopy depend on the risk of HSIL. In certain instances, if the risk is greater than 25% (based on current HPV and cytology results combined with past history), immediate treatment may be acceptable. If the risk of finding CIN grade 3 or greater (CIN3+) is above 4%, colposcopy is indicated. These "clinical action thresholds" consider the immediate risk of CIN3 or invasive cancer. Five-year risks are used for longer-term surveillance guidelines.[6]


There are no specific contraindications to a colposcopy except an active or untreated cervical or vaginal infection. Certain steps of the colposcopy procedure are excluded if a patient is pregnant. The endocervical curettage component is not performed due to potential risks of adverse effects on the pregnancy without substantial benefit. Furthermore, pregnancy can limit management options given that cervical excisional procedures are contraindicated during pregnancy unless cervical cancer is suspected. In that case, a shallow excisional procedure may be necessary.[7]


The equipment needed to perform an adequate colposcopy includes a vaginal speculum, a colposcope, 5% acetic acid, Lugol's solution, biopsy forceps, an endocervical speculum, a Kevorkian curette or endocervical brush, and solutions or methods to stem bleeding. The colposcope is a dissecting microscope that can magnify the cervical, vaginal, or vulvar tissue. Colposcopes differ in their optional features. Variation occurs with respect to lens types, computer-generated images, light filters, and even cameras to capture images or videos. Colposcopes should have 2 settings—low power and high power magnification—to evaluate a lesion. Most scopes have interchangeable magnifications at 10x and 18x. The scope should have a normal and green light filter to identify vascular patterns that can be difficult to recognize with white light.[8] 

There is a new procedural method called digital video colposcopy, which provides magnification and illumination with the help of a built-in camera and a strong light source (LED). Binocular eyepieces are not required, and the colposcopic image is viewed on a high-resolution video monitor. This procedure has several advantages, such as easy manipulation and visualization of images by several viewers simultaneously, including trainees and the patient. Additionally, it obtains a permanent record of the findings in the form of a replica of the image being seen by the examiner.

Five percent acetic acid is applied to the cervix with a cotton ball or large swab and allowed to soak for 1 to 2 minutes. Cells that are dysplastic dehydrate and turn acetowhite with the application of acetic acid. This process can cause the patient some minor discomfort. All areas of the cervix and upper vaginal tissue should be thoroughly inspected. Some colposcopists will apply Lugol's solution (an iodine-containing solution) that will highlight the dysplastic area with the lack of absorption of the brown solution, causing it to be more yellow. This is referred to as a "Schiller's test." A positive Schiller test is an area that is nonstaining with iodine.[9] 

An endocervical speculum may be needed to inspect the cervical os adequately. There is a variety of biopsy forceps available for cervical biopsy; the more common ones are Tischler cervical biopsy punch forceps, Burke biopsy forceps, or some variation of these.[8] There are different methods to stop the bleeding after a biopsy has been taken, including applying Monsel's solution, using silver nitrate, or even Bovie cauterization.


An experienced colposcopist is paramount to performing a reliable and accurate colposcopy. An assistant handling the instruments and specimen containers during the procedure is helpful but not required. A chaperone should always be in the room since colposcopy is an invasive procedure.


There is no required preparation for the patient having a colposcopy; however, it can be challenging to perform if she is on her menstrual cycle due to obscuring blood. Preparing the room with readily available equipment will expedite the patient’s visit.

Technique or Treatment

ASCCP has published standardization guidelines for the performance of colposcopy and makes recommendations for extensive and minimum requirements for a colposcopy. The colposcopist should examine the vulva, vagina, and cervix grossly without and with the application of 5% acetic acid.[10] The entire cervix and SCJ must be visualized for procedure adequacy. Both white light and a red-free (blue or green) filter should be applied to the visual field to identify any lesions.[10] 

Directed biopsies of lesions should be taken of each abnormal finding. Documentation should include the visibility extent, size, location, and description of each lesion (color/contour/border/vascular changes), presence or absence of acetowhitening, complete or incomplete visibility of the SCJ, documentation of biopsies and locations (if an endocervical curettage was performed), and finally the impression of the colposcopy (benign normal/low grade/high grade/cancer).[10] Application of Monsel’s solution or silver nitrate should be applied to the biopsy sites if persistently bleeding upon completion of the colposcopy. 

In 2011, the International Federation for Cervical Pathology and Colposcopy (IFCPC) introduced nomenclature and terminology to standardize colposcopic procedures performed by healthcare professionals (see Table 1. 2011 IFCPC Nomenclature).[11] Its use in general clinical practice was recommended and subsequently adopted.

The Swede scoring system is used to score the colposcopic findings and to have uniformity in the reporting system (see Table 2. Swede Scoring System). The total possible score is 10.[12] The performance and accuracy of colposcopic scoring are highly dependent upon the training and experience of the colposcopist.

The original study by Strander et al reported the sensitivity to predict CIN grade 2 and higher (CIN2+) with a Swede score ≥5 was 100%, and the specificity was 90% with a score ≥8. It was recommended that biopsy be reserved for a Swede score ≥5 (see Table 3. Use of Swede Score to Predict Histology).[13] 

Table 1. 2011 IFCPC Nomenclature

General assessment
  • Adequate or inadequate
    • If inadequate, a reason must be given (eg, cervix obscured by inflammation, bleeding, scar)
  • SCJ visibility
    • Completely visible, partially visible, not visible
  • Transformation zone types (1,2 and 3)
Normal colposcopic findings

Original squamous epithelium:

  • Mature
  • Atrophic columnar epithelium
  • Ectopy
  • Metaplastic squamous epithelium
  • Nabothian cysts
  • Crypt (gland) openings
Abnormal colposcopic findings    General principles

Location of the lesion:

Inside or outside the T-zone, location of the lesion by clock position

Size of the lesion:

Number of cervical quadrants the lesion covers, size of the lesion in the percentage of the cervix

  Grade 1 (minor) Thin acetowhite epithelium irregular, geographic border Fine mosaic, fine punctation
  Grade 2 (major) Dense acetowhite epithelium, rapid appearance of acetowhitening, cuffed crypt (gland) openings Coarse mosaic, coarse punctuation, sharp border, inner border sign, ridge sign
  Nonspecific Leukoplakia (keratosis, hyperkeratosis), erosion, Lugol’s staining (Schiller test): stained/nonstained 
Suspicious for invasion Atypical vessels, fragile vessels, irregular surface, exophytic lesion, necrosis, ulceration (necrotic), tumor/gross neoplasm   
Miscellaneous finding Congenital transformation zone, condyloma, polyp (ectocervical/ endocervical), inflammation Stenosis, congenital anomaly, posttreatment consequence, endometriosis

Table 2. Swede Scoring System 





Aceto uptake

Zero or transparent

Shady, milky (not transparent; not opaque)

Distinct, opaque white



Sharp but irregular, jagged, "geographical" satellites

Sharp and even, the difference in surface level, including "cuffing"


Fine, regular


Coarse or atypical

Lesion size

<5 mm

5 mm to 15 mm or 2 quadrants

>15 mm or 3-4 quadrants/endocervical undefined

Iodine staining


Faintly or patchy yellow

Distinct yellow

Table 3. Use of Swede Score to Predict Histology

Overall            Swede Score

Colposcopic Prediction of Probable Histology





High-grade/noninvasive cancer



High-grade/suspected invasive cancer



Colposcopy complications are most often related to an obscured visual field, severe atrophy, or scarring present. Procedural risks are low, including significant bleeding, infection, and long-term morbidity. There is potential harm in the performance of colposcopy by an unskilled clinician.[14] Anxiety and patient discomfort associated with the procedure can be significant and should not be underestimated. It can be challenging to ascertain if patients' negative feelings about colposcopy are related to the idea of HPV infection or the procedure itself. 

Professional training and continued experience in colposcopy are necessary for competency. The false-negative rate (missed high-grade squamous intraepithelial/invasive cancer) for colposcopy ranges from 13% to 69%.[15][16] Today, there are improved screening tests with cytology, molecular testing for HPV, and risk-based assessments. Therefore, there is less need for diagnostic testing with colposcopy, which creates less opportunity for ongoing training and experience for newly trained clinicians. This fuels an even greater need for experienced, skilled colposcopists. 

Even after a negative colposcopic examination, studies have reported subsequent high-grade disease. In a large trial for low-grade abnormalities, the sensitivity of initial colposcopy to detect high-grade disease in the subsequent 2 years was only 53%.[17]  Studies have shown a low level of agreement between the colposcopic impression of disease and final histology.[18][19] The use of multiple biopsies increases the accuracy of colposcopic diagnoses.[20] Endocervical evaluation with a curette or brush may also be helpful.[21] These studies highlight the need for continued observation based on the personalized risk of cytology, HPV testing, and past history.

Sources of Error in Colposcopy

Every colposcopic image reflects a specific tissue pattern resulting from the interaction of surface epithelium and stroma. Misinterpretation of patterns is the most common error in colposcopy. A flat, mild acetowhite grade 1 lesion is more likely to be overdiagnosed as these findings mimic immature or active metaplastic epithelium in young women, regenerative epithelium, subclinical HPV infection, and congenital transformation zone. If in doubt, such lesions must be biopsied. Colposcopy should be avoided during the regenerative period of epithelium following CO2 laser ablation, cryosurgery, or trauma. Another common error is making a diagnosis without completely visualizing the cervix in cases where it is obscured by an endocervical polyp or large retention cyst, or there is a stenosed internal os, and in cases of incomplete visibility of the SCJ.

Errors may occur in association with pregnancy due to physiological and morphological changes. Vasodilatation and congestion during pregnancy produce accentuated colposcopic patterns with more pronounced mosaics and punctations and enhanced acetic acid effect, which may mimic paraneoplastic lesions. These findings may be minimized by using a large speculum covered with a condom, quadrant-wise interpretation, and remembering that colposcopic changes in pregnancy are 1 grade higher than those in the nonpregnant population. Colposcopic biopsy and the use of an endocervical brush for cytology are safe if indicated during pregnancy, while endocervical curettage is contraindicated. 

Colposcopy can be difficult in postmenopausal women. An unsatisfactory colposcopy occurs in 25% of postmenopausal women due to the incomplete visibility of the SCJ and vaginal atrophy. Prior to colposcopy, it may be advisable to recommend these patients use vaginal estrogen to enhance the likelihood of achieving a satisfactory colposcopic examination.

Clinical Significance

Colposcopy is a diagnostic procedure performed due to an abnormal cervical screening test or a visible lesion seen on the cervix during an examination. This diagnostic procedure assists with formulating a management plan based on the biopsy results. Generally, all results can be observed or treated based on evidence-based guidelines. Low-grade lesions can be followed up and managed according to ASCCP guideline algorithms. High-grade lesions are treated depending on the patient’s age and fertility status.[22] 

A colposcopy considered inadequate for various reasons may lead to a more aggressive sampling of the cervical lesion with an excisional procedure of the cervix to attain the diagnosis. Invasive lesions should be referred to a gynecological oncologist for treatment options.

Pregnant patients will have treatment deferred until after delivery unless there is a specific concern for an invasive lesion.

Enhancing Healthcare Team Outcomes

Colposcopy is necessary to prevent cervical cancer from developing, but colposcopic expertise is not commonplace. Health professionals involved in colposcopy, including physicians, nurses, and pharmacists, must possess specialized skills. In the US, colposcopic services are delivered in diverse practice settings, including academic and nonacademic referral settings, primary care environments in urban and rural communities, and clinics funded by private and public resources.[23]  

Multiple types of clinical professionals can master this procedure. The training of various clinicians should be encouraged and ongoing. Developing a standardized approach to colposcopy is vital. Clinicians should adhere to recommended standardization and documentation of the procedure to improve patient care. Establishing clear protocols, guidelines, and clinical pathways ensures a consistent patient evaluation and management strategy. Future technological enhancement may continue to improve the reliability and validity of the colposcopic results.

All team members share the responsibility for patient safety and well-being. Healthcare professionals must collaborate to ensure seamless transitions and a comprehensive care plan for patients with abnormal findings. Enhancing patient-centered care in colposcopy involves honing skills, developing a clear strategy, fostering interprofessional communication, and coordinating care effectively. By prioritizing these aspects, healthcare professionals involved with colposcopy procedures can improve patient safety, outcomes, and overall team performance.



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