Extrathyroidal extension is independently associated with cervical lymph node metastasis in pediatric papillary thyroid carcinoma.

OBJECTIVE: To identify clinicopathologic predictors independently associated with cervical lymph node metastasis in pediatric papillary thyroid carcinoma. SUBJECTS AND METHODS: We performed a retrospective cohort including patients younger than 18 years who underwent total thyroidectomy for papillary thyroid carcinoma (PTC) (2013-2023) at a tertiary pediatric hospital in Brazil. Clinical and histopathologic variables were reviewed per World Health Organisation Classification 5th edition (2022) and the College of American Pathologists protocol (2023). Multivariable associations with cervical lymph node metastasis (LNM) were estimated using Firth's penalized logistic regression; discrimination was summarized by the area under the ROC curve (AUC) with 95% bootstrap confidence intervals. RESULTS: Thirty-two patients were included (median age, 14 years; 81% female). Cervical LNM occurred in 78%. Extrathyroidal extension (ETE) was associated with cervical lymph node metastasis in bivariate analysis (100% vs 59%; p = 0.007) and remained independently associated with cervical lymph node metastasis after adjustment for tumor T stage and lymphatic invasion (OR, 14.29; 95% CI, 1.28-2028.82; p = 0.028). CONCLUSION: ETE was independently associated with cervical lymph node metastasis in pediatric PTC and may justify closer postoperative surveillance.