Preoperative Clinical and Ultrasound Predictors of Central Lymph Node Metastasis in Papillary Thyroid Carcinoma: A Retrospective Study

This retrospective study explored preoperative predictors of central lymph node metastasis (CLNM) in papillary thyroid carcinoma (PTC) patients to guide individualized surgical decision-making, particularly for clinical N0 (no clinical evidence of lymph node metastasis (cN0) stage cases, where prophylactic central lymph node dissection remains controversial. After applying 1:1 propensity score matching (PSM) to balance baseline characteristics, 196 patients were included based on postoperative pathology, divided into CLNM-positive (n = 98) and CLNM-negative (n = 98) groups. Preoperative data collected included age, gender, body mass index (BMI), serum thyroid-stimulating hormone (TSH) level, anti-thyroglobulin antibody (TgAb), anti-peroxidase antibody, along with ultrasound indicators such as maximum tumor diameter, multifocality, tumor location (capsular contact), boundary, morphology, internal echo, calcification type (microcalcification or coarse calcification), blood flow signal grade, cervical lymph node length-to-diameter ratio, and lymph node gate structure. Multivariate logistic regression analysis revealed that maximum tumor diameter >1 cm [odds ratio (OR) = 3.26, 95% confidence interval (CI): 1.61-6.61], capsular contact (OR = 2.97, 95% CI: 1.44-6.13), microcalcification (OR = 2.64, 95% CI: 1.28-5.46), and serum TSH level >2.5 mIU/L (OR = 1.98, 95% CI: 1.01-3.88) were independent predictors of CLNM (all p < 0.05). Generalized estimating equations (GEE) and sensitivity analyses confirmed model robustness. Mediation analysis suggests that 32.7% of the statistical association between microcalcification and CLNM was mediated through tumor diameter. The combined predictive model achieved an area under the curve of 0.81, indicating good discriminative ability. In conclusion, preoperative tumor size, capsular contact, microcalcification, and elevated TSH level effectively predict CLNM risk in PTC patients. For cN0 stage patients, integrating these four indicators can guide rational decision-making regarding prophylactic central lymph node dissection, helping to avoid unnecessary surgery while reducing the risk of occult metastasis, thereby supporting more precise, risk-stratified surgical management in clinical practice.