Fig. 11.1 and 11.2
Acetowhite epithelium
Colour and duration: The degree to which the epithelium takes up the acetic acid stain is correlated with the colour tone or intensity, the surface shine, and the duration of the effect and, in turn, with the degree of neoplastic change in the lesion. Higher-grade lesions are more likely to turn dense white rapidly and remain visible longer than minor-grade lesions. A direct correlation exists between the intensity of the dull, white colour and the severity of the lesion. Grey white or dull oyster shell white, thickened epithelium indicates higher-grade lesion as compared to thin translucent epithelium of low-grade lesion.
If cytology report suggests glandular abnormality, carefully visualise the columnar epithelium. If intraepithelial neoplasia is present at the mouth of a glandular crypt, it may appear as a white-cuffed gland opening. These cuff gland openings should be easily distinguished from the faint rim of metaplastic epithelium surrounding normal gland openings (Fig. 11.3).
Fig. 11.3
Cuffed gland
Colposcopic classification of gland (crypt) openings: Gland openings of the uterine cervix have been classified into five types for colposcopy [10]:
Type I: Normal gland opening
Type II: Gland opening surrounded by a narrow white ring
Type III: Gland opening surrounded by a rather indistinct white ring
Type IV: Gland opening surrounded by a distinct and mostly thickened white ring (doughnut-like)
Type V: Solid gland opening
In a study by Scheungraber et al., CIN was found to be present in 5 % of cases with Type I/II gland openings and in 46 % of cases with Type III gland openings. The rate of CIN was as high as 96 % in cases with Type IV/V gland openings [11].
11.3.2 Margins of the Lesion
Margins of the lesion are an important predictor of severity of the lesion. Lesions with feathered, finely scalloped, angular, irregular or geographic margin, flat lesions with indistinct borders, satellite lesions not contiguous with SCJ and lesions showing irregular surface that appears condylomatous or micropapillary contour indicate low-grade lesion.
Flat or raised lesion of symmetrical shape, with well-delineated sharp and straight peripheral margin, indicates high-grade lesion. Rolled-out margins due to cell-to-cell fragile cohesiveness leading to epithelial edges detaching from underlying stroma and curling back on themselves are also a sign of high-grade lesion.
It is possible to have varying degrees of acetowhiteness within the same lesion known as inner border.
Inner Border Sign
The inner border is a dull, oyster white area, inside a less opaque acetowhite area (Fig. 11.4). The peripheral area represents an earlier, minor-grade change; the central area being the subsequent evolution of a high-grade CIN at the advancing edge of the new squamocolumnar junction with ageing [11]. Its significance lies during cervical biopsy. It is therefore important to sample the central lesion, because the central and peripheral lesions likely represent two different pathological processes in the same lesion.
Fig. 11.4
Lesion within a lesion
In a study by Scheungraber et al., in 70 % of women with inner border sign, CIN2 or 3 was confirmed histologically. Though the sensitivity of the sign for detection of CIN2 or 3 was 20 %, the specificity was 97 %. There was a significant association between women younger than 35 years and CIN2 or 3 with inner border sign [12].
11.3.3 Surface Contour
As lesions become more severe, their surfaces tend to be less smooth and less reflective of light, compared to normal squamous epithelium. The surfaces can become irregular, elevated and nodular relative to the surrounding epithelium.
Ridge Sign
It is an opaque lesion, adjacent to the squamocolumnar junction, which resembles mountain ridges (Fig. 11.5) [13, 14]. In a study by Scheungraber et al., CIN2 or 3 was diagnosed in 63.8 % of women with ridge sign. Sensitivity of ridge sign was 33.1 %, and specificity was 93.1 %.
Fig. 11.5
Ridge sign
11.3.4 Vascular Pattern
The arrangement of the terminal vessels in the stroma underlying squamous epithelium leads to colposcopic vascular findings which can be normal arborising vessels or abnormal vessels called punctate or mosaic [6]. Normal vessels usually run perpendicular to the surface.
Punctation is a colposcopic finding reflecting the capillaries in the stromal papillae that are seen end on and penetrate the epithelium.
When the stroma and accompanying capillaries are pressed between islands of squamous epithelium in a continuous fashion, a cobblestone pattern called mosaic is produced [15, 16].
If the punctation or mosaic is not located in the field of acetowhite epithelium, it is unlikely to be associated with CIN. These can be described either as fine or coarse.
Fine
If the vessels are fine in calibre, regular and located close together, it is more likely a benign or low-grade CIN.
Coarse
Sometimes, the two patterns are superimposed in an area so that the capillary loops occur in the centre of each mosaic ‘tile’. This appearance is called umbilication.
Many preinvasive lesions lack abnormal vessels and are identified only by acetowhite epithelium. So the lack of abnormal vasculature does not imply lack of significance. A high-grade lesion devoid of surface vessels is due to gradual compression and depression of the normal capillary looped vessels within a nuclear dense lesion, preventing them from being visualised. Also as the metabolic rate increases with high-grade lesions, vascular dilatation resists the constrictive effects of epithelial swelling, thus resulting in persistence of mosaic and punctuation patterns after application of acetic acid.
Certain non-neoplastic epithelium exhibiting punctation and mosaic includes:
Inflammatory conditions such as trichomoniasis (leopard skin appearance), gonorrhoea or chlamydial infections
Active immature metaplasia
11.4 Nonspecific Changes
11.4.1 Uptake or Rejection of Iodine
Normal squamous epithelium cells are glycogenated and appear mahogany brown on application of dilute iodine. Normal columnar epithelium, condylomata acuminata, high-grade lesions and many low-grade lesions do not contain glycogen, reject iodine and appear either mustard yellow or a variegated uptake pattern. It is considered as a nonspecific finding in the new IFCPC classification 2011 [7].
11.4.2 Leukoplakia
It is a white plaque visible grossly even without the application of 3–5 % acetic acid. It is often seen as a raised area and is not necessarily confined to the TZ. Cytologically, leukoplakia is represented by hyperkeratosis or parakeratosis. Histologically, it may be represented as thickened, keratinised squamous epithelium. Depending on its adherence to the underlying epithelium, leukoplakia may be dislodged during cytologic sampling or after wiping the cervix with a cotton swab. It occurs as a result of irritation to the epithelium due to trauma, chronic infection or neoplasia. It should be biopsied to rule out neoplasia [17, 18].
11.4.2.1 Colposcopic Features of Low-Grade Lesions (Minor Change) [19]
