The Role of Fine Needle Aspiration Cytology (Fnac) In the Evalution of Thyroid Lesions

Abstract

Objective: To determine the sensitivity, specificity and diagnostic accuracy of fine needle aspiration cytology in the management of thyroid lesions. Material and Methods: A prospective study of Fine needle aspiration cytology of the thyroid gland was undertaken to evaluate its diagnostic utility, during the period from June 2011 to December 2013 in the Department of Pathology, S.P. Medical College Bikaner. A total of 52 patients presenting with palpable thyroid nodule was included in the study. All the patients underwent fine needle aspiration of the nodule. Among 52 cases, 37 were biopsied subsequently and subjected to histopathological study. A comparison of FNA cytology and biopsy results was made. Results: Age of the patients ranged from 15-70 yrs with a mean age of 42.44 yrs. The majority of the patients were females in the present study with 45 (86.5%) females and 7 males, with a ratio of 6.41:1. Urban and rural distribution of sample population included 38 (73.1%) cases from rural and 14 (26.9%) cases from the urban population. Of the 52 cases of thyroid lesions, 39 were Non neoplastic lesions and 9 were Neoplastic lesions. Of the Non neoplastic lesions, 34 were Nodular colloid/ Adenomatous goiter, 4 Hashimoto thyroiditis, 1 neoplasm and 1 anaplastic neoplasm. Among 52 cases, 37 were biopsied subsequently and subjected to histopathological study. 28 cases were Non-neoplastic, 9 cases were Neoplastic. Out of 9 cases of Neoplastic lesions, 4 were Papillary carcinoma, 5 were Follicular adenoma. The diagnostic accuracy of non neoplastic and neoplastic lesions is 96.42% and 88.9% respectively. The sensitivity, specificity, positive predictive value and negative predictive value for FNAC of thyroid lesion neoplasm in the present study are 92.86%, 95.65%, 92.86% and 95.65% respectively. Conclusion: It helps to categorize Non-neoplastic from Neoplastic thyroid lesions. Its use has decreased the number of surgeries performed. FNAC of thyroid lesions has been shown to be safe, simple, cost effective and accurate method for the management of palpable thyroid lesions. However, in view of a small number of false negative results, the FNA results should be interpreted in the light of clinical findings. In case of doubt the true nature of the disease should be confirmed by biopsy.