Objective To determine the characteristics of thyroid nodules by using fine needle aspiration (FNA) biopsy and ultrasonography.
Patients and Methods FNAs of 1,004 patients with thyroid nodules between 2000 and 2007 were evaluated retrospectively. The surgical records of 101 of the patients were available and reviewed. The Odds ratios for nodule characteristics were calculated individually.
Results The sensitivity of FNA was 66.7% and the specifity was 95.2%. Positive predictive value was 72.7% and negative predictive value was 93.7%. Our diagnostic accuracy was 90.5%. Solitary nodules, irregular margins and microcalcifications were associated with increased risk of malignancy with Odds ratios 3.61 (95% CI: 1.25-10.42; p= 0,017); 5.44 (95% CI: 1.76-16.78; p= 0,003) and 39.29 (95% CI 8.32-185.47; p< 0.001) respectively. Macrocalcification, age, gender and thyroid status were not associated with increased risk of malignancy.
Conclusion Our data suggest that FNA is a reliable, reproducible and valid method to evaluate thyroid nodules and ultrasonographic features, especially microcalcification is a very important predictor of malignancy.