Objective   To investigate the clinical and pathological features of thyroid carcinoma(TC) coexistent with Hashimoto's thyroiditis(HT).

  Methods   A retrospective study was conducted on the clinical and pathological features of 218 patients with TC coexistent with HT.These patients were treated in The First Affiliated Hospital of Fujian Medical University between January 2006 and December 2010.

  Results   The TC with coexistence of HT cases accounted for 12.6%(218/1 731) of all the TC cases and 41%(218 / 531) in all the HT cases.Papillary thyroid cancer ranked first in the histological classification, accounting for 95.5%(208 / 218).The case of TC with coexistence of HT was more commonly observed in the female patients compared with TC without the coexistence of HT(94.1%vs.77.7%, P=0.000 1).The rate of ultrasonic diagnosis was very low in the cases(51.8%vs.75.1%, P=0.000 1), and the rate of pathological diagnosis by frozen diagnosis was also low(78.4%vs.94.8%, P=0.000 1), with a higher incidence of minimum cancer(43%vs.32.9%, P=0.043), a lower rate of nodal metastasis(55.0%vs.63.3%, P=0.048), and earlier AJCC / UICC staging(stageⅠ: 80.7%vs.67.1%;stageⅣ: 4.1%vs.8.4%, P=0.000 1).

  Conclusion   A close relationship exists between TC and HT.TC complication with HT would have several clinical features, such as a tendency of occurrence in females, more difficult preoperative diagnosis, and a more favorable prognosis.Total or near total thyroidectomy combined with central cervical lymph node dissection should be used as the basic mode of surgery for TC coexistent with HT.