Correlation Between Fine Needle Aspiration Cytology with Histopathological Findings of Thyroid Gland Swellings
Author(s): Hasan Ali, Rafiul Alam, Mohammad Abubakar Siddique, Utpaul Kumar Sarkar, Abul Kashem, Anup Talukder, Amzad Hossain, Mahede Hasan
Background: Fine needle aspiration cytology (FNAC) is a minimally invasive method to assess thyroid gland swellings by extracting cells with a thin needle. It helps distinguish between benign and malignant thyroid lesions before surgery. This study aimed to assess the agreement between cytological results obtained through fine needle aspiration cytology (FNAC) and the corresponding histopathological outcomes.
Methods: This cross-sectional study was conducted in the Department of Otolaryngology and Head-Neck Surgery, Sir Salimullah Medical College Mitford Hospital, Dhaka, Bangladesh from June 2020 to June 2021. A total of 100 patients with thyroid swelling, indicated for fine needle aspiration cytology (FNAC) and subsequent thyroid surgery, were purposively enrolled in this study. Data were analyzed and presented in both qualitative and quantitative formats using SPSS version 20.0.
Results: In the ultrasound study, most cases had benign characteristics. By thyroid scanning, 78% showed warm nodules. FNAC diagnosis found nodular goiter in 64% of cases. Histopathology revealed 76 true negatives and 4 false negatives among 80 disease-negative cases. All 10 malignant cases were confirmed as malignant (true positives). Among 10 suspicious lesions, 8 were true positives and 2 were false positives. The analysis showed specificity, PPV, NPV, and accuracy of 97.44%, 90.00%, 95.00%, and 94.00%, respectively.
Conclusion: FNAC is a sensitive, specific, and accurate initial diagnostic test for evaluating thyroid swellings. While cytodiagnostic errors can occur due to overlapping features, awareness of potential pitfalls can minimize these errors. Suspicious results should be confirmed with histopathology. Additionally, benign FNAC results should be cautiously interpreted due to the possibility of false negatives.