Fine needle aspiration cytology--a reliable diagnostic tool in the diagnosis of thyroid gland enlargements.

To evaluate the accuracy and efficacy of fine needle aspiration cytology (FNAC) in the diagnosis of Thyroid gland enlargements. A retrospective analysis was done at Department of Pathology, Government Medical College and General Hospital, Anantapur, Andhra Pradesh, India. One hundred and fifty cases were included in this study. However in 10 cases aspirate was unsatisfactory and in 20 cases surgery was not performed and these cases were excluded from study. A total of 120 cases included in the final study. Detailed history, physical examination, routine investigations and other details of 120 patients were collected. FNAC with minimum two passes were performed in each case. Staining done with Haematoxylin and Eosin stain and Papanicolaou stains. FNAC smears and histopathology slides were reviewed. Among 120 cases 100 (83.66%) were reported cytologically as benign and 20 (16.66%) were malignant. But histologically 98 (81.66%) were benign and 22 (18.33%) were malignant. Commonest benign lesion of thyroid in both cytology and histology was nodular colloid goiter. Follicular adenoma was the second commonest one. Among malignant conditions papillary carcinoma was the commonest one in our FNAC samples, follicular carcinoma was the commonest in our histopathology samples. Four cases of false positive and 6 cases of false negative were observed. Sampling errors were mainly responsible for these false negative diagnoses. FNAC showed an accuracy of 96.6%, sensitivity 75%, specificity 95.83%, positive predicative value (PPV) 81.81% and negative predicative value (NPV) of 93.81%. Our results were similar to other international studies and suggest that FNAC is more specific and sensitive in detecting thyroid malignancy. Therefore its useas a reliable diagnostic test cannot be over emphasized. FNAC is an accurate and reliable diagnostic tool to evaluate the cause of Thyroid gland enlargements provided strict adherence to adequacy criteria are maintained.