Role of fine needle aspiration cytology in the diagnosis of papillary carcinoma thyroid: A retrospective study from north-east India

Abstract

Background: Thyroid cancer is the most common endocrine malignancy, and 85% of thyroid cancers are papillary thyroid carcinoma (PTC) making it the most common malignant tumor among all thyroid cancers. Objectives: To analyze the efficacy of fine needle aspiration cytology (FNAC) as the first-line diagnosis of PTC. Materials and Methods: A retrospective study was conducted over a period of 10 years 6 months from January 2007 to June 2017. All the cases of thyroid nodules, which are suspected to have thyroid malignancy from history and clinical examination, and morphologically proven cases of PTC either on FNAC or histopathology were included in the study. FNAC results were compared with the definitive histological diagnosis, which was considered the gold standard. The cytological evaluation and reporting of thyroid lesions were done in accordance with the Bethesda system of reporting thyroid cytopathology. Results: A total of 106 cases were included in the study. Out of the 106 cases, FNAC was inadequate in 8 cases (7.54%), benign in 18 cases (16.98%), atypia of undetermined significance/follicular lesion of undetermined significance in 2 cases (1.88%), follicular neoplasm (FN)/ suspicious for FN in 8 cases (7.54%), suspicious for malignancy in 27 cases (25.47%), and malignant in 43 cases (40.56%). Out of the 106 cases, 75 cases (70.75%) were PTC, which had histopathological correlation. The sensitivity and specificity of FNAC were 87.14% and 77.27%, respectively. Conclusion: FNAC is helpful in triaging the suspicious thyroid lesions for further management. FNAC is quite useful in diagnosis of PTC.