Department of Pathology, Integral Institute of Medical Sciences and Research, Integral University, Lucknow, Uttar Pradesh, India

In surgical practice, thyroid abnormalities are frequently encountered, and Fine Needle Aspiration Cytology (FNAC) is frequently employed as the preliminary diagnostic test. By classifying thyroid lesions as inflammatory, benign, or malignant, FNAC helps doctors decide which treatments-such as surgery or medicine-are best for their patients. This study attempted to determine the diagnostic accuracy in patients with thyroid gland swelling, as well as the morphology of thyroid lesions by FNAC and their distribution by age and sex. A one-year retrospective study was carried out in a tertiary care center's Department of Pathology from July 2022 to June 2023. Using a data collection tool, the age, gender, and diagnosis of 152 patients who had Fine Needle Aspiration procedures were identified from their medical records.138 (90.7%) of the 152 patients were men, and 14 (9.3%) were women. The average age was 39.78 ± 12.6. Lesion types comprised 92.7% non-neoplastic lesions and 7.3% malignant lesions. Goiter accounted for 62.5% of all non-neoplastic lesions. The majority of patients (29.6%) experienced hypothyroidism symptoms in addition to thyroid gland hypertrophy. Additionally, there was one case of papillary carcinoma (0.6%). Twenty-third-century individuals exhibited the majority of thyroid lesions (26.3%). In the fourth and fifth decades of life, goiter would manifest. In the third decade, Hashimoto's and lymphocytic thyroiditis were most frequently observed. With an AUC of 0.93, FNAC further revealed high accuracy in evaluating lesions, with true positive cases being 89%, specificity of 98%, PPV of 97%, and NPV of 95%. The study emphasize the need for evacuation of palpable thyroid lesions by FNAC as it can prove to be indispensable tool for early diagnosis of malignancy.