Analysis of cytological false negatives of carcinoma of cervix

Introduction: Cervical carcinoma is one of the leading malignancies affecting the women of India. Since the Papanicolaou (Pap) test can very effectively detect the prolonged phase of carcinoma in situ, current policy suggests that all women should have this test done at regular intervals. Monitoring cytohistological discrepancies is a useful quality assurance tool in cytology laboratory. Cervical cancer has been successfully reduced by routine screening and medical intervention.
Aims and objectives: This present study was done to study the prevalence of cytohistological discrepancy in histologically proven cases of carcinoma cervix and to identify the causes for false negativity in the cytological examination in histologically proven cases of carcinoma cervix.
Materials and methods: This study was conducted in the Department of Pathology, Mahatma Gandhi Institute Of Medical Sciences , Sevagram , Maharashtra. This study was done on 209 biopsy proven cases of carcinoma cervix over a period of two years. The original cytological diagnosis of smears available in these cases were co- related with the biopsy results.
Results: In the pre-review, in 80.3% cases the diagnosis of carcinoma was rendered on initial screening in cytology. Cytohistological discrepancies were observed in 19.6% accounting for a false negative rate of 19.6% and a false negative fraction 0.196 %. After post review, the false negative rate reduced to 11.62% and the frequency of the different types of errors were calculated.
Conclusion: The level of agreement between cytology and the histology diagnosis may be used as a measure of laboratory quality. To the best of our knowledge, data on factors
associated with cytohistologic discrepancy in Pap smear are limited. Therefore, we conducted this study to evaluate the factors associated with cytohistologic discrepancy in Pap smears and to determine the rate of cytohistologic discrepancy and ways to reduce the false negatives.