METHODS: This retrospective study collected 6762 thyroid nodules from 6493 consecutive patients who underwent biopsy between January 2013 and December 2013. The initial biopsy with ≥1 year of follow-up was used as the gold standard for benign diagnosis. For our study purpose, we analyzed 2747 (57.0%, 2747 of 4822, 532 women, 2111 men; 229 malignant and 2518 benign) thyroid nodules diagnosed by initial biopsy with 28.2 ± 9.1 (range, 12-41) months of follow-up. We calculated the malignancy probability of thyroid nodules by using various malignancy risk stratification systems.
RESULTS: The overall calculated thyroid malignancy rate was 8.3% (229 of 2747). Initially biopsy-proven benign nodules exhibited a ≤3.0% malignancy probability when assessed as \"low suspicion\" by Korean-TIRADS (K-TIRADS), \"low suspicion\" by the ATA guideline, and \"very probably benign\" by the French TIRADS guideline and gave a score of ≤3 by the web-based TIRADS.
CONCLUSIONS: When initially biopsy-proven benign nodules exhibit a \"low suspicion\" US pattern and low malignancy probability, as stratified by various TIRADS guidelines, imaging surveillance instead of second biopsy is warranted.
CONCLUSIONS: • One biopsy is sufficient for initially biopsy-proven benign nodules. • Repetitive biopsy is necessary for imaging-pathology mismatched nodules. • Scoring risk stratification permits personalized management.