A comparison of liquid-based cytology and conventional smears in fine needle aspiration cytology of thyroid lesions: Diagnostic efficacy and pitfalls

Abstract

Introduction: Fine needle aspiration cytology is an unrivalled method of preoperative triage of thyroid lesions. The use of liquid-based cytology (LBC) is now extended to nongynecological samples due to the advantages of lesser screening time, clearer background, and potential use of leftover material for ancillary investigations. Aims and Objectives: The aim of the study is cytomorphological comparison of LBC and conventional method and cytohistopathological correlation in surgically resected cases. Materials and Methods: Fine needle aspiration was done in 100 patients. Conventional smears were prepared followed by LBC from the remaining material. The smears from both the methods were scored semiquantatively and were compared cytomorphologically. Pearson's Chi-square test and fisher's exact test were used for P value calculation using SPSS software. A P Results: LBC had more unsatisfactory as well as suspicious for malignancy cases. The cells in LBC were in three-dimensional clusters and singly scattered with loss of cellular architecture. The nuclei were shrunkun and hyperchromatic with spilling of cytoplasm. The background colloid, blood as well as lymphocytes were mostly washed off. Immunocytochemisrty results were not affected by the LBC procedural steps. Conclusion: It was very difficult to come to a conclusive diagnosis with the help of LBC alone. It can be useful for ancillary investigations like immunocytochemistry as in this study. Thus, it can be used as a supplement to conventional method rather than replacing it.