QUALITY-ASSURANCE STUDY OF SIMULTANEOUSLY SAMPLED, NON-CORRELATING CERVICAL CYTOLOGY AND BIOPSIES

As part of a quality assurance study, we reviewed 223 cases of simulta neously sampled cervical smears and biopsies that showed a significant lack of correlation for squamous dysplasia or carcinoma. In 153 of th e 223 cases (68.6%), the cytology was negative and the biopsy positive . After review of the specimens, errors in this group were found to be of the following types: sampling 64%, interpretive 29%, and combined sampling and interpretive 7%. In the remaining 70 cases (31.4%), the b iopsy was negative and the Papanicolaou smear positive. In these cases , the following types of errors occurred: sampling 54%, interpretive 3 3%, and combination 13%. Twenty-nine of these 70 patients showed dyspl asia on follow-up material. These findings indicate there are a signif icant number of false-negative Papanicolaou smears, mostly because of sampling problems. There are few false-positives. In cases of positive Papanicolaou and negative biopsy, dysplasia is likely to be present i n subsequent samples.