Value of repeated US-guided fine-needle aspiration (US-FNAB) in the follow-up of benign thyroid nodules: a real-life study based on the MoCyThy (Modena's Cytology of the Thyroid) DATABASE with a revision of the literature.

Re-biopsy of benign nodules confirmed the benign nature in most cases. In case of discordant cytology, relocation in indeterminate category was the most common. The histological diagnosis of cancer occurred in one quarter of nodules surgically removed, with a low overall clinically significant miss rate. Thus, a small percentage of false negatives exists; males and subjects with US suspicious nodules should be carefully followed-up, considering case by case re-biopsy possibility.