Objective：To study the clinical features, diagnosis and treatment of  patients with nodular goiter concomitant thyroid cancer.
Methods：The clinical data of 142 cases with concomitant thyroid cancer in 1 859 cases of nodular goiter admitted from January 2008 to January 2011 were retrospectively analyzed.
Results：All the 142 patients underwent surgical treatment, of which, there were 112 cases of primary surgery and 30 cases of secondary surgery. The ratio of men to women was 1∶3.1, and the patients predominantly manifested as nodular goiter. Fifty-five cases (38.7%) were suspected of having concomitant thyroid cancer as suggested by preoperative ultrasound examination, of which 21 cases (18.7%) had nodular psammomatous calcification. Twelve cases had cervical lymph node enlargement. Ninety patients underwent high-resolution color Doppler ultrasound examination, of which 68 cases (75.6%) were suspected of having malignant lesion. Fine needle aspirations (FNA) were performed in 45 cases and the correct diagnostic rate was 48.9%. The pathological examinations of intraoperative fast frozen section were performed in 138 patients, with accuracy rate of 96.4%, 5 false negative cases and no false positive case. Of the patients with thyroid cancer, 83 cases were unifocal and 59 cases were multifocal, lesions less than 2.0 cm accounted for 75.3%, the main pathological type was papillary carcinoma (75.4%), and 64 cases showed lymph node metastasis. The surgical procedures comprised ipsilateral total lobectomy combined with isthmusectomy, ipsilateral total lobectomy combined with isthmusectomy plus contralateral subtotal lobectomy or total thyroidectomy, and ipsilateral or bilateral central compartment (level VI) lymph node dissection. The patients with enlarged cervical lymph nodes and suspected of having cervical lymph node metastasis before or during surgery underwent additional modified neck dissection. After surgery, all the 142 patients received replacement therapy with levothyroxine, 101 cases of whom were also given radioactive131I ablative therapy. Eight cases underwent reoperation due to relapse.One case died of pulmonary metastasis of the thyroid cancer during the postoperative follow-up period of 6 months to 3 years.
Conclusions：Papillary cancer is the most common type of the concomitant thyroid cancer in patients with nodular goiter and the lesion usually is less than 2.0 cm. Preoperative ultrasonography, FNA and pathological examination of intraoperative fast frozen section can increase the detection rate and effectively reduce the misdiagnosis of concomitant thyroid cancer in nodular goiter. Rigorous follow-up of those patients with nodular goiter can improve the early detection rate of concomitant thyroid cancer.