Cytology, colposcopy, and directed biopsy: what are the limitations?

Positive predictive rate of colposcopic examination of the cervix uteri: an overview of literature

Study of literature revealed that the positive predictive rate of the colposcopic impression is better as the cervical lesion is more severe. When directed biopsies are taken, the positive predictive rate of colposcopy increases considerably. For microinvasive disease, the positive predictive rate is quite poor, probably because of the absence of characteristic features. Large loop biopsies diagnosed all cases of microinvasive disease missed by directed biopsies, but this technique has the disadvantage of considerable "overtreatment" when integrated in the management of all patients with abnormal cytology. The restrictions of colposcopy are the invisibility of the squamocolumnar junction and observer variability in the assessment of the impression. The levels of agreement among experienced colposcopists are in the same range as those in cytological and histopathological diagnosis. It is concluded that colposcopy is an indispensable tool in the management of premalignant cervical disease, as long as the restrictions of the technique are kept in mind by the colposcopist.

The accuracy of colposcopically directed biopsy in diagnosis of CIN

During the last decade there has been an increasing interest in the use of the colposcope. A quality-control study for the evaluation and understanding of the limitations of cytology and colposcopy in our clinic is presented. The results in 132 patients are analysed and compared to previous reports from the literature. Cytologic results correlated with the histological diagnosis only in 47% of the patients. Colposcopically directed biopsies were accurate in 88.8% when the entire squamocolumnar junction was visualized. The accuracy of the directed biopsies in patients with unsatisfactory colposcopy was 58.3%. In the presence of a Gardnerella vaginalis cervicitis the colposcopic accuracy decreased to 70.9%.

The treatment of cervical intraepithelial neoplasia using the carbon dioxide laser

A total of 423 patients with cervical intraepithelial neoplasia (CIN) have been treated with a carbon dioxide laser in the out-patient colposcopy clinic. Thirty patients required two or more treatments. Outcome has been assessed in 408 patients followed for more than 1 year. Sixteen patients (4%) have had a recurrence of CIN. Failures were not related to age, parity or size of lesion.

Some observations on the value of endocervical curettage performed as an integral part of colposcopic examination of patients with abnormal cervical cytology

A total of 259 patients underwent endocervical curettage as an integral part of colposcopic examination of patients with abnormal cervical cytology. The transformation zone was entirely visualized in 140 patients (54.1 per cent), and, in 8.6 per cent of this group, the endocervical curettings were abnormal. On no occasion did the endocervical curettage harbor the worst lesion when compared to the histology of the ectocervical biopsy, cone biopsy, and hysterectomy specimens. In 117 patients (45.2 per cent), the transformation zone could not be visualized in its entirety, and in 57.3 per cent the endocervical curettings were abnormal. In one patient of this group invasive carcinoma was present in the endocervical curettage, and in another patient invasive carcinoma was present in both the ectocervical biopsy and the endocervical curettage. Thus, when the entire transformation zone is not visualized in its entirety or at all, endocervical curettage appears to be of value since a frank invasive carcinoma may be diagnosed and a cone biopsy avoided.