False-negative Papanicolaou smears from women with cancerous and precancerous lesions of the uterine cervix

The occurrence from 1980 to 1989 of false-negative Papanicolaou smears in women with cancerous and precancerous lesions of the uterine cervix was studied. The 4,781 cases of cancer (2,814 invasive carcinomas and 593 carcinomas in situ) and precancerous lesions (418 severe dysplasias, 748 moderate dysplasias and 208 mild dysplasias) included 70 cases (1.5%) with false-negative smears. These 70 cases included 43 invasive carcinomas (61.4%), 17 carcinomas in situ and adenocarcinomas in situ (24.2%), and 10 dysplasias (14.4%); all were diagnosed histologically. The mean age of women with false-negative smears was 44.1 +/- 13.7 years. Review of the original cytologic samples showed a screening error in 41 cases (58.5%), an interpretation error in 2 cases (2.9%) and a sampling error in 27 cases (38.6%). Methods for eliminating false-negative smears are discussed.