FINE NEEDLE ASPIRATION CYTOLOGY AND HISTOPATHOLOGICAL CORRELATION OF NODULAR LESIONS OF THYROID: A STUDY

Thyroid swelling being the most common neck swelling, a retrospective study was done to assess the role of Fine Needle Aspiration Cytology in diagnosing the nature of thyroid lesions and comparing its results with histopathological findings. It was observed that FNAC is the investigation of choice in thyroid swellings and has excellent patient compliance, is simple and quick to perform in outpatient department and is cost effective with high degree of sensitivity and specificity. MATERIALS AND METHODS This is a retrospective study comparing cytology and corresponding histopathology reported in 60 cases of nodular thyroid lesions. The statistical analysis included sensitivity and specificity and accuracy in nodular thyroid lesions. RESULTS On cytological examination of the 671 cases, initial diagnosis/impression as non-neoplastic was given for 616 cases (91.80%) and neoplastic for 47 cases (7.00%) in which 17 cases (36.17%) were benign and 28 cases (59.57%) were given as malignant, 5 cases were reported as suspicious for malignancy and for 5 cases samples were inadequate for a cytological diagnosis. Sensitivity of FNA in non-neoplasm lesions 92.5%, follicular neoplasm 87.5% and malignancies 68.42%. The specificity of FNA in non-neoplastic lesion is 100%, in follicular neoplasm is 96% and in malignancy 100%. Accuracy in FNAC for non-neoplastic lesion and follicular neoplasm 95% and malignancy 91%. CONCLUSION It was observed that FNAC is a vital reliable tool, safe and accurate method to evaluate nodular thyroid lesions. It greatly influences the treatment decision. In spite of accuracy of FNAC in differentiating between benign and malignant lesions, certain pitfalls were highlighted in diagnosing follicular neoplasm, which constitutes a "Gray zone" and papillary carcinoma and follicular carcinoma. We hope that a better understanding of these pitfalls wound help avoiding them in future and will contribute to better patient care.