Management and outcomes of small U3-U4 thyroid nodules: do sub-centimetre U3 nodules require biopsy?
Noon Nassr, Kala Kumaresan, Sinnappa Gunasekaran, Nalinda PanditaratneAbstract
Objective
To evaluate management and outcomes of small (≤20 mm) U3–U4 thyroid nodules in UK practice and assess whether selected sub-centimetre U3 nodules require biopsy.
Methods
Retrospective cohort study at a UK district general hospital, including U3–U4 thyroid nodules ≤20 mm identified in 2022, with a follow-up to June 2025. The primary outcome was histologically confirmed thyroid malignancy. Secondary outcomes included fine-needle aspiration, cytology and surgical intervention.
Results
Eight-one nodules (73 patients) were included. Sixty-one nodules (75.3 per cent) underwent fine-needle aspiration and 31 nodules (38.3 per cent) underwent surgical procedure. The investigation was driven by ultrasound grade rather than size. Sub-centimetre nodules were less likely to be resolved by fine-needle aspiration or surgical procedure. Among the resected nodules, 26 out of 31 (83.9 per cent) were malignant, with no difference across size bands.
Conclusion
Management of small U3–U4 nodules is determined by ultrasound grade and cytology rather than size. These findings support the consideration of a surveillance-first approach for selected sub-centimetre U3 nodules, provided the appropriate follow-up pathways are in place.