Diagnostic Utility of Cell Block Technique as an Adjunct Technique to Cytological Smears in Evaluation of Thyroid Aspirates on Fine Needle Aspiration Cytology

Abstract

Background: Fine needle aspiration cytology is a standard screening technique for the diagnosis and assessment of thyroidnodules. However, this approach has some drawbacks, such as false negative or positive outcomes and high rates ofunsatisfactory results.Objective: To describe the utility of cell block technique as an adjunct to conventional smear in the cytodiagnosis of thyroidepithelial lesions.Material and Methods: This Descriptive Cross-sectional study was done at the Pathology department of Saidu Group of TeachingHospital Saidu Sharif Swat from 1st November 2017 to 31st April 2018. Fine needle aspirates for both the direct smear and cell blockwere collected simultaneously from 60 patients, through non- probability convenient sampling. All patients having clinicallyenlarged thyroid, solitary or dominant thyroid nodule were included in the study.All patients below 22 years old and patients who didnot give informed consent were excluded. Ethical clearance was obtained from the ethical research committee before carrying outthe study. Written informed consent was taken from all the participating patients.Cellularity, obscuring background material, morphological and architectural preservation as well as cytodiagnosis on direct smearand cell block technique were compared. Data were analyzed using SPSS software version 21. McNemar's chi-square test wasapplied for significant difference. P-value of = 0.05 was considered significant.Results: Male to Female ratio was 1:7.5, (13%: 87%). The age ranged from 22 to 81 years with a mean age of 44.9 and standarddeviation of ±14.5 years. The study showed that the cell block technique has high cellularity, minimal obscuring background, betterarchitectural preservation and poor morphological preservation on cell block in comparison to direct smear. The majority of thecases were benign on both techniques. The unsatisfactory rate was reduced in cell block technique and showed additionalinformation in 13 % cases.Conclusion: The study demonstrated no significant difference in the diagnostic utility of both techniques.Keywords: Cell Block Cytopathology, FNAC, Mair et al criteria