Cell block as an adjunct to conventional Papanicolaou smear for diagnosis of cervical cancer in resource-limited settings

Objective: To assess the utility of indigenously prepared cell blocks (CBs) as an adjunct to a conventional smear test in providing a reliable diagnosis of clinically suspicious cervical cancer in resource-limited settings. Methods: Eighty-six clinically suspicious cervical cancer cases underwent a conventional smear test, CB preparation from residual cellular samples and biopsies at the same sitting. Correlations were performed between these modalities in order to derive the sensitivity and specificity of the CB technique to diagnose cervical cancer. Observation & Results: Out of 86 clinically suspicious cervical cancers, 72 (83.7%), 70 (81.4%) and 67 (77.9%) cases were diagnosed as malignant on tissue biopsies, CBs and smears respectively. CB-biopsy agreement in the diagnosis of malignancy was feasible in 87.5% of the cases while CB-Pap smear agreement was feasible in 92.5% of the cases. Sensitivity and specificity of CB preparation to diagnose malignancy was 92.5% and 100%, respectively, when the smear was taken as the reference test (excluding the unsatisfactory smears). When biopsy was taken as the gold standard, the sensitivity and specificity of CBs were 87.5% and 100% respectively (excluding the unsatisfactory biopsies). In 8/19 cases where the smear diagnoses were either unsatisfactory or atypical squamous cells/atypical glandular cells, CBs picked up malignant lesions. Conclusion: CBs prepared from the residual cellular sample of conventional cervical scrapes augment the sensitivity of the smear test. When used as an adjunct to the smear, CBs aid in providing a reliable diagnosis of cervical cancer in the majority of the clinically suspected cases and thus the biopsy load can be reduced significantly in resource-poor settings.