Evaluation of thyroid fine needle aspiration for pathological concordance

Introduction:Thyroid nodules are a common problem and the first thyroid malignancy presentation in clinical practice. This study aimed to evaluate FNABs performed in patients with thyroid nodule during the years 1995 to 2006 for cytohistologic concordance.Material and Methods:In this study, we reviewed the files of 1150 patients with thyroid nodule and finally 218 patients underwent thyroid surgery following FNAB biopsy and were chosen for the study.Results:Four cytologic diagnostic categories were used and the rates of these categories were as follows: benign, 57.8 percent; suspicious for malignancy, 20.2 percent; malignant, 19/7 percent and non-diagnostic, 1.4 percent. We obtained a sensitivity of 72.5 percent, a specificity of 83 percent and an accuracy of 76 percent. The false negative rate was 19 percent and the false positive rate was 24 percent.Conclusion:The results of this study showed that diagnostic value (sensitivity, specificity, accuracy) of FNAB in our region in comparison with other countries is low. The most imprtant result is the low rate of nondiagnostic (1.4 vs. 17 percent) and high rate of false negative reports (19 percent) in comparison with other studies (5.2 percent). It seems that FNA is an accurate and cost effective procedure; yet, it can be more accurate with better sampling and more attention to false negative and inadequate results. is It is suggested that a standard classification and clinical data should be taken into account, especially in the case of suspicions results.