Objective: Our objective was to test the hypothesis that accurate cytological prediction of cervical intraepithelial neoplasia grade 3 (CIN3) is related to the size of the atypical transformation zone.
Patients and methods: Data on 340 women in whom CIN3 was diagnosed after large-loop excision of the transformation zone were recorded prospectively on a computerized database. These data were studied with regard to such variables as lesion size, age, parity, contraception use, and smoking status.
Results: No association was demonstrated between cytological findings and lesion size in accurately predicting CIN3 lesions. A weak association between cytological findings and age was demonstrated: Cytology is more likely to predict CIN3 accurately in women 25 years or older than in women younger than 25 years.
Conclusions: Accurate cytological prediction of CIN3 is not related to the size of the atypical transformation zone seen at colposcopy. The CIN3 lesions may be present as discrete foci within a background of low-grade changes.