The Sensitivity and Specificity of Fine Needle Aspiration Cytology (FNAC) and Histopathology for the Diagnosis of Thyroid Nodule

Abstract

Background: FNAC is a minimal invasive, quick tool fordiagnosis of thyroid nodule with excellent patient’scompliance. But its diagnostic is still debatable. Objective:To evaluate the sensitivity and specificity of fine needleaspiration cytology (FNAC) and histopathology for thediagnosis of thyroid nodule. Materials and Methods: Thisstudy was conducted on ENT patients at Dhaka MedicalCollege from July to December 2017. This study was crosssectional. Subsequently, a sample size of 73 was determinedbased on the established eligibility criteria. A pre-designed,peer-reviewed data collection form was created forconducting interviews. Data were compiled, managed, andpresented in tables and figures. FNAC's sensitivity,specificity, and predictive values were determined usinghistodiagnosis as the gold standard. Results: 21 out of 73patients (28.76%) were aged between 30 and 39. 67.13% of the sample (n=73) were femaleand 32.87% were male. The male-to-female ratio was 1:2. The majority of the patients(75.34%) belonged to the middle class, while 20.54% were from the poor class. Among thepatients, 39.72% were housewives, 35.61% were employed, and 19.17% were students. TheFNAC exhibited high sensitivity (94.73%), specificity (100%), positive predictive value(100%), negative predictive value (98.18%), and low positive and negative likelihood ratios (0 and 0.052, respectively). All 55 benign FNAC findings were accurate and consistent with thehistodiagnosis, except for one case where malignancy was detected upon histology.Conclusion: This research suggests using FNAC as a standard diagnostic technique for allthyroid nodule patients. For more accurate findings, longer-term research with a largenumber of study participants may be conducted.