Objective: We aimed to evaluate the prognostic value of thyroid fine needle aspiration biopsy (FNAB) in the diagnosis of pathologic lesions.
Methods: Data from 1 078 consecutive patients (female : male ratio, 9:1) who underwent thyroidectomy were retrospectively analyzed. All patients had preoperative thyroid FNAB. Unilateral and bilateral FNAB were performed in 872 and 206 patients, respectively, resulting in 1 284 cytologic aspirates, which were compared to postoperative histology. Risk factors for malignancy (age, sex, single nodule, or nodule in multinodular goiter) were evaluated.
Results: 203 (15.81%) aspirates were non-diagnostic. 768 (59.81%) were benign; 112 (8.72%) were atypical; 170 (13.24%) were follicular neoplasms, 5 (0.4%) had suspicion of malignancy; and 26 (2.02%) were malignant tumors on FNAB. The calculated risk of malignancy in each group was: 1.97%, 1.84%, 7.15%, 12.35%, 60%, and 100%. There were 2.02% false negative and 0.15% false positive results. Diagnostic discrepancies occurred in the follicular neoplasm group, of 86 biopsies (0.15%).
Conclusion: FNAB is the primary method of preoperative diagnostics of thyroid tumors, as it allows many patients to avoid thyroidectomy. In addition, it helps the operating surgeon to decide the extent of surgical resection.