Clinical value of repeat Pap smear at the time of colposcopy

To determine the clinical value of a repeat (second) Pap smear at the time of colposcopy in the management of patients with recent cytologic abnormalities.

A study of paired Pap smears and their corresponding cervical biopsies during a two-year period, commencing in June 1996, was undertaken. Pap smears and cervical biopsies from 614 patients were evaluated in the Department of Pathology, Royal Darwin Hospital, Northern Territory, Australia. To maintain uniformity, the cytologic and histologic findings were assessed according to the Bethesda System.

The original (first) Pap smears included 288 high grade and 326 low grade lesions. The second smears showed 200 high grade, 221 low grade, 167 normal and 26 unsatisfactory cases. Punch biopsies revealed 242 high grade, 300 low grade and 72 inflammatory/reactive lesions. The changes noted in the second Pap smears and in the punch biopsies in the group originally diagnosed as having high grade disease were generally less advanced. The second Pap smears and corresponding cervical punch biopsies showed more advanced changes in the group originally diagnosed as having low grade disease. Removal of part of the abnormal epithelium during the first Pap smear and the desire of the colposcopist not to damage the surface epithelium prior to performing a cervical biopsy may account for some of these findings. Sampling errors and morphological misinterpretation may explain some of the findings.

In the second smears, new cases of high grade abnormality were discovered mainly in patients with low grade changes on the first smears. Therefore, a second Pap smear at the time of colposcopy is justifiable in the group with low grade changes on the first smear.