False-negative results of conventional Papanicolaou cervical cytology in women with cervical conization

Abstract

Objective：The conventional Papanicolaou smear seems to be more accurate for detecting a high-grade squamous intraepithelial lesion (HSIL) than a low-grade squamous intraepithelial lesion (LSIL). The purpose of this study was to investigate false-negative results of conventional Pap smear cytology in women with cervical conization. Methods：This study was performed in Gynecologic Oncology Clinic of the Department of Obstetrics and Gynecology at Dankook University Medical Center from July 1, 1994 to December 31, 2004. 260 women from age 22 to 75 years had undergone conventional Papanicolaou cervical cytologic test and cervical conization. Conization was performed using ‘cold-knife cone' method or ‘large electrosurgical excision procedure (LEEP) cone' method. The cervical cytology were studied in comparison with histology of conization specimens. Results：Of the 260 histologic diagnoses, there were 41 (15.8%) diagnoses of chronic cervicitis, 8 (3.1%) of CIN 1, 18 (6.9%) of CIN 2, 150 (57.7%) of CIN 3, 38 (14.6%) of SCC, 2 (0.8%) of AIS, 1 (0.4%) of ACC, and 2 (0.8%) of ASC. Pap cytology showed sensitivity of 97.9-98.2%, specificity of 4.9-6.7%, and false-negative rate of 1.8-2.2% according to the variables. Conclusion：Significantly false-negative rate of Pap cytology in women with conization was very low. And so, conventional Pap cytology is still clinically efficient for screening high-grade cervical lesions with adequate sampling technique.