Colposcopy is a widely used diagnostic procedure, primarily in the assessment of women with abnormal cervical cytology. It is used by appropriately trained individuals using techniques that allow a full assessment of the abnormality and plan for further investigation or treatment. Certain key features are specifically looked for, and a colposcopic impression formed. Using a systematic approach to the colposcopic assessment can improve the diagnostic accuracy. In this chapter, we review various factors and meta-analyses in relation to the diagnostic performance of colposcopy. Newer technologies are being developed that will assist the clinician in assessing the colposcopic changes. Quality assurance of the training and practise of colposcopy is important to maintain appropriate management for women with cytological abnormalities.
Introduction
Colposcopy is a diagnostic procedure used for assessing the lower genital tract and vulva under illumination and magnification. It was introduced as a technique in 1925 by Hinselmann. The primary aim of colposcopy is diagnostic validation of premalignant disease of the cervix, usually after an abnormal cervical cytology or a clinically suspicious lower genital tract. It can, however, be used for assessment of other pathologies such as human papilloma virus (HPV) infection, genital warts and Lichen sclerosus. In some countries, it is used as a basic screening tool at the time of gynaecological examination. In women who have a cervical cytology sample carried out, 10% will have some degree of abnormality and many of these will warrant further investigation. In the context of the woman presenting with abnormal cervical cytology, the aims of colposcopy are to confirm or refute the cytological suspicion of cervical intraepithelial neoplasia (CIN); recognise or rule out invasive cancer; recognise or rule out glandular disease; determine the precise geographical or anatomical position of the transformation zone; monitor progression or regression of CIN; and facilitate in deciding extent and type of treatment and follow-up thereof. See International Federation for Cervical Pathology and Colposcopy classification for colposcopy ( Table 1 ).
| I. | Normal colposcopic findings |
| Original squamous epithelium | |
| Columnar epithelium | |
| Transformation zone | |
| II. | Abnormal colposcopic findings |
| Flat acetowhite epithelium | |
| Dense acetowhite epithelium a | |
| Fine mosaic | |
| Coarse mosaic a | |
| Fine punctation | |
| Coarse punctation a | |
| Iodine partial positivity | |
| Iodine negativity a | |
| Atypical vessels a | |
| III. | Colposcopic features suggestive of invasive cancer |
| IV. | Unsatisfactory colposcopy |
| Squamocolumnar junction not visible | |
| Severe inflammation, severe atrophy, trauma | |
| Cervix not visible | |
| V. | Miscellaneous findings |
| Condylomata | |
| Keratosis | |
| Erosion | |
| Inflammation | |
| Atrophy | |
| Deciduosis | |
| Polyps |
a Indicates the characteristics of high-grade changes (dense acetowhite epithelium, coarse mosaic, coarse punctuation, thick leukoplakia, atypical vessels); characteristics of low-grade changes are faint acetowhite epithelium, fine mosaic, fine punctation, and thin leukoplakia.
Technique: colposcopic assessment parameters
The colposcope is a binocular device that allows magnification and illumination of the cervix. By applying various stains to the cervix, abnormalities can be identified. These include benign, precancerous and malignant changes. All colposcopes follow similar principles. They provide magnification between 6- and 40-fold. Low and medium magnification are used for initial assessment; high magnification (20-fold plus) is used to detect the finer detail of vascular patterns. A green filter, where available, further allows better visualisation of vasculature on the cervix.
The cervix and upper vagina are examined at low magnification. Any excess mucus, blood or vaginal discharge should be removed using a dry or saline-soaked cotton wool ball. Presence of gross lesions and leukoplakia should be identified. The green filter should be used to assess the vascular pattern (low to high power). Benign lesions that are visualised should be noted. These include nabothian follicles, cervical polyps, warts and cysts.
Acetic acid (3–5%) is gently applied to the cervix with saturated cotton wool balls on sponge forceps or a jumbo swab, or by using a spray or syringe. The acetic acid is left in contact with the cervix for 10 seconds. The cervical landmarks and any atypical areas should be mentally mapped, or when considered necessary and resources permit, photographic evidence can be obtained. Lugol’s iodine (1% iodine, 2% potassium iodide, 97% distilled water) may be used to further delineate atypical epithelium, which contains little or no glycogen and therefore fails to take up the iodine stain. This is referred to as ‘Schiller’s test’. A Schiller-positive test is an area that is non-staining with iodine. The vagina should be examined as the speculum is removed. Immediately after assessment, the findings are recorded, ideally in a standard format, as follows ( Fig. 1 ): (1) reason for referral; (2) grade of cytological abnormality; (3) whether the colposcopic examination is satisfactory defined as the entire squamocolumnar junction and the upper limit of any cervical lesion having been seen; (4) presence or absence of vaginal, endocervical extension, or both; (5) was there any acetowhite epithelium? If yes, document its site and size in graphic format; (6) was Schiller’s test positive; (7) assess the degree of change; (8) the colposcopic impression of lesion grade; (9) proposed management: repeat assessment or treatment.
Technique: colposcopic assessment parameters
The colposcope is a binocular device that allows magnification and illumination of the cervix. By applying various stains to the cervix, abnormalities can be identified. These include benign, precancerous and malignant changes. All colposcopes follow similar principles. They provide magnification between 6- and 40-fold. Low and medium magnification are used for initial assessment; high magnification (20-fold plus) is used to detect the finer detail of vascular patterns. A green filter, where available, further allows better visualisation of vasculature on the cervix.
The cervix and upper vagina are examined at low magnification. Any excess mucus, blood or vaginal discharge should be removed using a dry or saline-soaked cotton wool ball. Presence of gross lesions and leukoplakia should be identified. The green filter should be used to assess the vascular pattern (low to high power). Benign lesions that are visualised should be noted. These include nabothian follicles, cervical polyps, warts and cysts.
Acetic acid (3–5%) is gently applied to the cervix with saturated cotton wool balls on sponge forceps or a jumbo swab, or by using a spray or syringe. The acetic acid is left in contact with the cervix for 10 seconds. The cervical landmarks and any atypical areas should be mentally mapped, or when considered necessary and resources permit, photographic evidence can be obtained. Lugol’s iodine (1% iodine, 2% potassium iodide, 97% distilled water) may be used to further delineate atypical epithelium, which contains little or no glycogen and therefore fails to take up the iodine stain. This is referred to as ‘Schiller’s test’. A Schiller-positive test is an area that is non-staining with iodine. The vagina should be examined as the speculum is removed. Immediately after assessment, the findings are recorded, ideally in a standard format, as follows ( Fig. 1 ): (1) reason for referral; (2) grade of cytological abnormality; (3) whether the colposcopic examination is satisfactory defined as the entire squamocolumnar junction and the upper limit of any cervical lesion having been seen; (4) presence or absence of vaginal, endocervical extension, or both; (5) was there any acetowhite epithelium? If yes, document its site and size in graphic format; (6) was Schiller’s test positive; (7) assess the degree of change; (8) the colposcopic impression of lesion grade; (9) proposed management: repeat assessment or treatment.
Atypical transformation zone
The atypical transformation zone is the area of the cervix of which its limits define cervical intraepithelial neoplasia. The transformation zone is a dynamic region of the epithelium, and deviation to abnormality occurs within the unstable metaplastic epithelium. However, there is no one feature that defines a distinct histological abnormality, and it is the overall appearance that is important. Any condition that causes increased cellular division, abnormal cellular metabolism or increased vascularisation can produce atypical colposcopic findings in cervical epithelium. There are three types of transformation zone: A type 1 transformation zone is completely ectocervical and fully visible, and may be small or large; A type 2 transformation zone has an endocervical component, is fully visible, and may have an ectocervical component that may be small or large; A type 3 transformation zone has an endocervical component that is not fully visible and may have an ectocervical component that may be small or large.
Colcospic features
Colposcopoic features suggestive of low-grade disease (minor change), high-grade disease (major change), and invasive cancer are presented in Tables 2–4 .
| A smooth surface with an irregular outer border |
| Slight acetowhite change, slow to appear and quick to disappear |
| Mild, often speckled iodine partial positivity |
| Fine punctation and fine regular mosaic |
| A generally smooth surface with a sharp outer border |
| Dense acetowhite change, which appears early and is slow to resolve; it may be oyster white |
| Iodine negativity, a yellow appearance in a previously densely white epithelium |
| Coarse punctation and wide irregular mosaics of differing size |
| Dense acetowhite change within columnar epithelium may indicate glandular disease |
| Irregular surface, erosion, or ulceration |
| Dense acetowhite change |
| Wide irregular punctation and mosaic |
| Atypical vessels |
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
