Background and Objectives: Thyroid is unique in being largest endocrine organ amenable to physical examination and is affected by plethora of disorders ranging from developmental to neoplastic. After diabetes mellitus, commonest of the endocrine disorders are of thyroid gland. Solitary thyroid nodule leads to cosmetic issues, compression on adjacent organs or can have malignant potential. FNAC has been foremost diagnostic tool compared to others, requiring no admission/anesthesia. This study is done to determine age and sex distribution of thyroid lesions with clinical correlation, to evaluate diagnostic accuracy of FNAC in diagnosing lesions of thyroid. Materials and Methods: This Prospective study (June 2014 – November 2016) comprised of 162 cases, referred to Navodaya Medical College Hospital & Research Centre, Raichur and FNAC of thyroid lesions were done with histopathological correlation in 78 patients and statistical analysis was performed in 71 cases, as 7 cases with cytological diagnosis of follicular neoplasm and hurthle cell neoplasm were excluded because cytologically it cannot be differentiated as benign /malignant. Results: Thyroid lesions were common in age group of 31-40 years, with female predilection (83.95%), neck swelling was predominant clinically (100%) and least common was fever and pain. Among the non neoplastic lesions-nodular goiter (93 cases; 57.40%) was common followed by lymphocytic thyroiditis (13 cases; 8.02%), hashimotos thyroiditis (11 cases; 6.79%), Multi nodular goiter (8 cases; 4.93%), hyperplastic nodule (6 cases; 3.70%) Colloid cyst (5 cases; 3.08%) colloid nodule (3 cases; 1.85%) and in Neoplastic follicular neoplasm (6 cases; 3.70%), Hurthle cell adenoma (1 case; 0.61%) papillary carcinoma (10 cases; 6.17%), medullary carcinoma (2 case; 1.22%), (papillary carcinoma with hashimotos thyroiditis (1 case; 0.61%) and anaplastic carcinoma (1 case; 0.61%) were seen. By comparing the result of FNAC and histopathology, FNAC has sensitivity of 80%, specificity 96.4% & PPV 85.7% and NPV 94.7% and accuracy of 93.0%. Conclusion: Thyroid cytology proves to be a reliable, simple and cost-effective first line diagnostic procedure with high patient acceptance and without complications. The ideal test should have a sensitivity and specificity of 100%. The closest method to ideal test is, thus, FNAC which has high sensitivity and specificity. However, a combination of both FNAC and Ultrasound will give optimal results and avoid mismanagement. Thus FNAC is followed as first line pre-operative procedure due to its simplicity, cost-effectiveness & good diagnostic accuracy.

Keywords: Fine Needle Aspiration Cytology (FNAC), Thyroid Swellings.