The following characteristics are important in identifying the abnormal or atypical transformation zone (TZ):

• Vascular pattern (punctation, mosaicism, atypical vessels)
• Intercapillary distance (it increases with the severity of the lesion)
• Color tone (increased whiteness indicates more nuclear activity)
• Surface contour (advanced lesions have more irregular surfaces)
• Character of the border between normal and abnormal epithelium (severe lesions have sharper borders)

One or more of the following features are usually present in the atypical TZ:

• Acetowhite epithelium
• Punctation
• Mosaicism
• Leukoplakia or hyperkeratosis
• Atypical blood vessels

All the above-mentioned findings together establish the colposcopic diagnosis, and correlation among cytology, histology, and colposcopy is necessary (Ferris, Shier) .