ROLE OF FNAC IN THE DIAGNOSIS OF THYROID MAILGNANCY AND ITS COMPARISON WITH HISTOPATHOLOGY

Abstract

Objective:

To find out the accuracy of FNAC and its comparison with histopathology in diagnosing thyroid malignancy.

Materials and Methods:

This prospective study was conducted in 56 patients attending the ENT and Head & Neck Surgery, Out Patient Department, Shree Birendra Hospital, Chhauni, Kathmandu, Nepal from August 2010 to June 2012. Clinically diagnosed thyroid swelling patients were subjected to FNAC. Based on clinical findings and FNAC, patient underwent appropriate surgery, then the FNAC finding was compared and correlated with the final HPE report.

Results:

The majority of cases were in their third decade (30.36%), with female predominance,  female to male ratio was 6:1. The maximum number of cases was diagnosed to have colloid goitre (60.71%) by FNAC, followed by papillary carcinoma thyroid (30.36%) and benign proliferative thyroid disease (5.36%). However, histopathology confirmed the predominant cases to be of papillary carcinoma thyroid (48.21%) followed by colloid goitre (32.14%). The overall prevalence of malignancy was 62.5% by HPE and 37.5% by FNAC. Accuracy score was 82.14% in the prediction of neoplasia.

Conclusion:

FNAC is a simple preoperative test commonly done in diagnosing thyroid swelling. In cases of clinically suspicious malignancy of thyroid, FNAC is suggested before definitive surgery so as to plan adequate surgery at the first sitting itself. When compared to the final HPE report, sensitivity of FNAC was 62.96% while specificity was 100%; accuracy was noted to be 82.14%. Predictive value of a positive test and negative tests was 100 % and 74.35% respectively.

Keywords: fine needle aspiration cytology (FNAC), histopathological examination (HPE), papillary carcinoma thyroid (PCT)