[Colposcopy of CIN and microinvasive cervical carcinoma]

The colposcopist must distinguish between two patterns: nonsuspicious findings and suspicious findings. With experience, the colposcopist will succeed more and more in distinguishing between the two, thereby markedly reducing the number of biopsies. Suspicious findings are not synonymous with abnormal findings because the latter are not always due to premalignant lesions. A number of features are of value in the different diagnosis of colposcopic findings: sharp borders, response to acetic acid (white epithelium), surface contour, appearance of blood vessels, surface extent (size), combinations of abnormalities, iodine uptake, and keratinization. The diagnostic features described above can be expressed to varying degrees, and can be found singly or in combination. The more distinct a feature is and the greater the variety of features seen in combination, the higher the index of suspicion. Attempting to differentiate between the various grades of CIN (SIL) colposcopically is more questionable, as these lesions are regarded now as forming a spectrum of the same biologic process.