Abstract: Background and purpose: The incidences of papillary thyroid carcinoma (PTC) and Hashimoto’s thyroiditis (HT) both have been continuously increasing, and their relationship is the hot topic in current academic world. This research aimed to investigate the clinicopathologic relationship between PTC and HT. Methods: A retrospective analysis was conducted based on clinicopathologic data of 306 patients who underwent first thyroid carcinoma radical resection in Department of Head and Neck Surgery, Cancer Hospital of University of Chinese Academy of Sciences from 2014 to 2015. All patients were histologically diagnosed as having papillary thyroid carcinoma, and 42 patients were histologically diagnosed with concomitant Hashimoto’s thyroiditis. Results: Female patients were elder than male patients(46.2 years vs 41.9 years). Compared with PTC patients without HT, PTC patients with concomitant HT had a greater female preponderance (93% vs 77%), more central lymph nodes (5.0±3.4 vs 2.5±2.7), elevated preoperative level of thyroid-stimulating hormone (TSH) ［(3.28±1.91)μU/mL vs (2.12±1.29)μU/mL］, and increased positive rate of thyroid peroxidase antibody (TPOAb) (55% vs 14%) and thyroglobulin antibody (TgAb) (69% vs 13%). Among PTC patients with central lymph node metastasis, the number of metastatic central lymph nodes significantly correlated with the total number of central lymph nodes (Pearson correlation coefficient=0.582). Multivariate logistic analysis indicated that male, younger age and extrathyroidal extension were risk factors of central lymph node metastasis in PTC patients. Conclusion: The presence of HT is not a prognostic factor for PTC. Elevated TSH level in PTC patients with concomitant HT suggests HT may be one of the risk factors for PTC. The correlation of metastatic central lymph node number and total central lymph node number suggests lymphadenitis may be a risk factor of lymph node metastasis for PTC.

Key words: Papillary thyroid carcinoma, Hashimoto’s thyroiditis, Thyroid-stimulating hormone, Central lymph node, Prognosis