Rehydration of air-dried smears with normal saline: An alternative for conventional wet fixation method in cervical cytological study

Context: Papanicolaou (Pap) smear is an effective exfoliative cytological investigation done for early recognition of cervical cancer. It also plays role in diagnosis of inflammatory lesions of cervix. Aims: The aim of this study is (1) to compare the cytomorphological features in conventional Pap smear (C-PAPS) and rehydrated air-dried Pap smear (RADPS) and (2) to evaluate the efficacy of RADPS in cytodiagnosis of cervical lesion by comparing with cytomorphological features of conventional wet-fixed Pap smear. Subjects and Methods: Paired cervical smears were prepared for 247 patients. One was labeled as C-PAPS and another was labeled as RADPS. Comparison of both smears was done for various cytomorphological parameters. Results: Out of 247 smears, 2.4% RADPS and 7.3% C-PAPS were reported as unsatisfactory. Red blood cell (RBC) background was present in 2% of RADPS and 42% of C-PAPS. Cytolysis and air-drying artifact were observed more in C-PAPS amounting to 2% and 4% in RADPS and 11% and 15% in C-PAPS. Cytoplasmic staining (97% RADPS vs. 94% C-PAPS) was superior in RADPS. Cell border, nuclear border, and chromatin of squamous and endocervical cells were better appreciated on RADPS compared to C-PAPS, and also statistically significant difference was observed. Conclusion: Rehydrated air-dried technique can be satisfactory alternative for conventional wet fixation method which can be followed routinely or in conjugation with C-PAPS, especially in cervical screening programs.