Role of Colposcopy

Chapter 2

Role of Colposcopy

2 Role of Colposcopy

Colposcopy is a diagnostic procedure to visualize the epithelia of the lower genital tract with magnification and adequate illumination. Applications of acetic acid and Lugol’s iodine (Schiller’s test) are useful parts of the examination. The aim of colposcopy is to identify and plan the treatment of premalignant (intraepithelial) diseases of the cervix, vagina, vulva, and perianal region. Worldwide, colposcopy is performed in different settings and for different indications. Competency in colposcopy avoids overtreatment and promises better patient outcomes. Colposcopy can be applied in a variety of contexts.

2.1 Routine Colposcopy

We believe colposcopic inspection of the cervix should be an integral part of the gynecologic examination. This approach gives the examiner an appreciation of the dynamic processes that occur at the cervix at the different stages of life as well as experience and confidence in assessing colposcopic findings. All lesions—whether inflammatory, condylomas, polyps, preinvasive, or invasive—are better seen when magnified and optimally illuminated. With practice, the colposcopist can react quickly and accurately detect visible lesions. Many believe colposcopy should not be used as a screening method where the likelihood of finding cancer precursors is low, but it is easy to combine colposcopy with routine cytology. The diagnostic accuracy of cytology and colposcopy can then be assessed by performing a biopsy of colposcopically suspect findings. We believe this practice is superior to colposcopy restricted to evaluating abnormal smears because it can detect lesions missed by cytology. In contrast to cytology, colposcopy can localize suspicious lesions. If cytology is positive but the ectocervix and the vagina are normal, an endocervical lesion can be predicted. In this way, cytology can select patients for biopsy. Also, it is possible to direct a smear for cytology under colposcopic guidance so that a colposcopic lesion can be scraped directly with an Ayre’s spatula, or the endocervical canal can be sampled when there are no lesions on the ectocervix. There is also no doubt that the quality of cytology can be improved by the simultaneous use of colposcopy. It is instructive to follow up on given patient over years.

2.2 Colposcopy to Evaluate an Abnormal Pap Smear

In many countries, colposcopy is used primarily to evaluate women with an abnormal Pap smear. Most countries use the Bethesda nomenclature for cervical cytology (Table 2.1). In this setting, the goal is to identify and localize lesions suspected on the basis of abnormal cytologic findings. In a meta-analysis, the sensitivity of colposcopy for the detection of high-grade squamous intraepithelial lesion (HSIL) was 96%, with a specificity of 48%. Table 2.2 shows the 2014 WHO histologic terminology for epithelial cervical neoplasia.

Colposcopy is no substitute for histologic evaluation, and a biopsy should be taken from the area of the most clinically severe abnormality of any lesion.

2.3 Colposcopy to Evaluate Patients Positive for HPV

Testing for high-risk types of human papillomavirus (HPV) is more sensitive for the detection of HSIL than cytology. The association between infection with high-risk types of HPV and HSIL and cervical cancer is so strong that HPV testing has become an important part of the management of women with cytologic abnormalities. Furthermore, the detection of HPV after treatment for HSIL is an accurate predictor of relapse, significantly more sensitive than repeated cytology.

The limitation of HPV testing is that women who test positive for high-risk (HR) HPV carry only a small risk of underlying HSIL or cancer. Dual staining for p16INK4a/Ki-67 increases specificity and maintained sensitivity for the diagnosis of HSIL or adenocarcinoma in situ (AIS) compared with testing for HR-HPV. Most experts agree that women positive for both high-risk HPV and p16INK4a/Ki-67 should be referred for colposcopy to verify or rule out a lesion.

Because there is a strong evidence base that HPV testing is advantageous in primary screening of women aged 30 years or older, HPV screening is coming to augment or supplant cytologic screening. This trend looks likely to spread worldwide so that we will likely see a large number of women positive for high-risk HPV referred for colposcopic evaluation of the cervix.

In women with low-grade cytologic smears, normal colposcopic findings are associated with a high negative predictive value, even in the presence of HPV infection.

2.4 Colposcopy to Evaluate Abnormal Cytologic Findings during Pregnancy

Colposcopy is safe in pregnancy and is performed with the intention of ruling out invasive cancer. Cumulative data suggest that expectant treatment of pregnant women with an abnormal Pap smear (i.e., delaying treatment of preinvasive changes until after pregnancy) is safe.

2.5 Colposcopy to Evaluate Lesions before Treatment

Apr 16, 2018 | Posted by in OBSTETRICS | Comments Off on Role of Colposcopy
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