A Study of Comprasion of Conventional Cytology with Liquid Based Cytology of Thyroid FNAC – A Study of 100 Cases

ABSTRACT

Background: Fine Needle Aspiration (FNA) cytology of the thyroid has been increasingly utilized for the investigation of thyroid lesions. FNA of the thyroid gland is considered to be most cost effective and accurate primary diagnostic procedure for thyroid nodules. In the recent years many approaches has been devised to improve the quality of thyroid FNA cytology because the conventional smear (CS) is subject to error in sample collection and slide preparation. The liquid based cytology (LBC) originally developed for the application of gynaecologic cervical smears, has progressively gained for application of both non gynaecologic and fine needle aspiration cytological material. According to the Wilcoxon signed ranked test for thyroid lesions LBC was not useful in goitre and infectious lesions. It gave better results in anaplastic and medullary carcinoma. So conventional smear is more sensitive, specific and accurate than LBC. Methods: in this prospective study, we had 100 cases of thyroid. In each case, two passes were performed. The first pass was for CS and the second pass yielded material for LBC. Both CS and LBC smears were compared for cellularity, background blood and necrotic cell debris, cell architecture, informative background, presence of a monolayer of cells and nuclear and cytoplasmic details and test on an for statistical analysis. Results: Diagnostic accuracy was better in CS compared withLBC smears as CS was most sensitive (93.18%) and accurate (91.75%) method for analysis of thyroid while LBC method is sensitive (89.04%) and accuracy (86.59%).Conclusion: Conventional smear is more sensitive, specific and accurate than LBC because LBC introduce more cytological artifacts to thyroid aspirates.