Routine pathological nodal status evaluation significantly modifies 2025 ATA risk category of patients with unifocal...

Occult lymph node metastases occur in up to 50% of patients with clinically node-negative papillary thyroid carcinoma eligible for thyroid lobectomy. Nevertheless, the 2025-ATA guidelines discourage routine prophylactic ipsilateral central neck dissection in clinically node-negative clinical T1b-T2 low-risk disease. This multicentric retrospective study evaluated the impact of routine ipsilateral central neck dissection on recurrence risk stratification in patients with unifocal clinically node-negative clinical T1b-T2 papillary thyroid carcinoma eligible for thyroid lobectomy. Among 9,028 thyroidectomies performed in four referral centres, 264 patients met the inclusion criteria. Lymph node metastases were found in 135 (51.1%) patients, with extranodal extension in 8.9% of node-positive cases. Median tumour size was 12 mm. Final histopathology showed pT1a disease in 88 (33.3%), pT1b in 165 (62.5%), and pT2 in 11 (4.2%). Extrathyroidal extension, vascular invasion, multifocality, and aggressive histologic variants were observed in 12.1, 60.6, 43.2, and 18.9%, respectively. According to the 2025-ATA risk stratification system, excluding pathologic nodal status, 60 (22.7%) patients were low risk, 31 (11.8%) low-intermediate risk, 170 (64.4%) intermediate-high risk, and 3 (1.1%) high risk. After inclusion of nodal status, 54 (20.4%) were low risk, 24 (9.1%) low-intermediate risk, 171 (64.8%) intermediate-high risk, and 15 (5.7%) high risk (p < 0.001). Overall, 8% of patients experienced risk upgrading, and > 70% were classified in higher-risk categories. Pathologic nodal assessment substantially modifies recurrence risk stratification in clinical node-negative T1b-T2 papillary thyroid carcinoma eligible for thyroid lobectomy, supporting routine ipsilateral central neck dissection for staging and tailored surgical decision-making.