The colposcopist should be well aware that invasive cancers are more common in older women and in those referred with high-grade cytological abnormalities. Large high-grade lesions, involving more than three quadrants of the cervix, should be thoroughly investigated for the possibility of early invasive cancer, especially if associated with atypical vessels. Other warning signs include the presence of a wide abnormal transformation zone (greater than 40 mm2), complex acetowhite lesions involving both lips of the cervix, lesions obliterating the os, lesions with irregular and exophytic surface contour, strikingly thick chalky white lesions with raised and rolled out margins, strikingly excessive atypical vessels, bleeding on touch or the presence of symptoms such as vaginal bleeding.
An advantage of performing a digital examination of the vagina and cervix before inserting the vaginal speculum is the opportunity to feel for any hint of nodularity or hardness of tissue. After the speculum is inserted, the cervix should have normal saline applied and the surface should be inspected for any suspicious lesions. Then the transformation zone should be identified, as described in Chapter 6
and Chapter 7
. Colposcopic examination proceeds in the normal fashion (Chapter 6
and Chapter 7
) with successive applications of saline, acetic acid and Lugolís iodine solution and careful observation after each.
The colposcopic findings of preclinical invasive cervical cancer vary depending upon specific growth characteristics of the individual lesions, particularly early invasive lesions. The early preclinical invasive lesions turn densely greyish-white or yellowish-white very rapidly after the application of acetic acid (Figure 8.1
). The acetowhiteness persists for several minutes.
One of the earliest colposcopic signs of possible invasion is blood vessels breaking out from the mosaic formations and producing irregular longitudinal vessels (Figure 8.2
). As the neoplastic process closely approaches the stage of invasive cancer, the blood vessels can take on increasingly irregular, bizarre patterns. Appearance of atypical vessels usually indicates the first signs of invasion (Figures 8.1
). The key characteristics of these atypical surface vessels are that there is no gradual decrease in calibre (tapering) in the terminal branches and that the regular branching, seen in normal surface vessels, is absent. The atypical blood vessels, thought to be a result of horizontal pressure of the expanding neoplastic epithelium on the vascular spaces, show completely irregular and haphazard distribution, great variation in calibre with abrupt, angular changes in direction with bizarre branching and patterns. These vessel shapes have been described by labels such as wide hairpin, waste thread, bizarre waste thread, cork screw, tendril, root-like or tree-like vessels (Figure 8.5
). They are irregular in size, shape, course and arrangement, and the intercapillary distance is substantially greater and more variable than that seen in normal epithelium.
If the cancer is predominantly exophytic, the lesion may appear as a raised growth with contact bleeding or capillary oozing. Early invasive carcinomas that are mainly exophytic tend to be soft and densely greyish-white in colour, with raised and rolled out margins (Figures 8.4
). Surface bleeding or oozing is not uncommon, especially if there is a marked proliferation of atypical surface vessels (Figures 8.1
, 8.4 and 8.7
). The bleeding may obliterate the acetowhiteness of the epithelium (Figures 8.2
, 8.4 and 8.7
). The atypical surface vessel types are varied and characteristically have widened intercapillary distances. These may take the form of hairpins, corkscrews, waste thread, commas, tadpole and other bizarre, irregular branching patterns and irregular calibre (Figures 8.1
, 8.5 and 8.7
). The abnormal branching vessels show a pattern of large vessels suddenly becoming smaller and then abruptly opening up again into a larger vessel. All of these abnormalities can best be detected with the green (or blue) filter and the use of a higher power of magnification. Proper evaluation of these abnormal vessel patterns, particularly with the green filter, constitutes a very important step in the colposcopic diagnosis of early invasive cervical cancers.
Early preclinical invasive cancer may also appear as dense, thick, chalky-white areas with surface irregularity and nodularity and with raised and rolled out margins (Figure 8.6
). Such lesions may not present atypical blood vessel patterns and may not bleed on touch. Irregular surface contour with a mountains- and valleys- appearance is also characteristic of early invasive cancers (Figures 8.2
, 8.6 and 8.7
). Colposcopically suspect early, preclinical invasive cancers are often very extensive, complex lesions involving all the quadrants of the cervix. Such lesions frequently involve the endocervical canal and may obliterate the external os. Infiltrating lesions appear as hard nodular white areas and may present necrotic areas in the centre. Invasive cancers of the cervix rarely produce glycogen and therefore, the lesions turn mustard yellow or saffron yellow after application of Lugolís iodine (Figures 8.1
, 8.4 and 8.7
If a biopsy is taken of a lesion that is suspicious for invasive carcinoma and the report is negative for invasion, the responsibility rests with the colposcopist to ensure that a possibly more generous biopsy and an endocervical curettage (ECC) be taken at a subsequent examination. It is mandatory to take another biopsy if the pathologist reports that there is inadequate stromal tissue present on which to base a pathological decision as to whether invasion is present.
Advanced, frankly invasive cancers do not necessarily require colposcopy for diagnosis (Figures 3.4
, Figures 3.5
, 3.6 and 8.8
). A properly conducted vaginal speculum examination with digital palpation should establish the diagnosis so that further confirmatory and staging investigations may be performed. Biopsy should be taken from the periphery of the growth, avoiding areas of necrosis, to ensure accurate histopathological diagnosis.