Clinical characteristics and surgical resection of multifocal papillary thyroid carcinoma: 168 cases.

PURPOSE To investigate clinical characteristics and surgical treatment of multifocal papillary thyroid carcinoma. METHODS A total of 648 patients diagnosed with papillary thyroid carcinoma were enrolled, 168 with multifocal papillary thyroid carcinoma. Clinicopathological factors including gender, age at diagnosis, family history of thyroid tumor, multiplicity and bilaterality of tumor, extra-thyroidal extension, lymph node involvement and other factors were statistically compared. RESULTS The incidence of multifocal papillary thyroid carcinoma was 25.9% and 117 presented with bilateral thyroid gland lesions. In multifocal group, patients had a higher ratio of male subjects, family history of thyroidal tumor, neck lymph node metastasis and extra-thyroidal extension by B-ultrasound. Solitary papillary thyroid carcinoma tended to be with a higher rate of benign goiters. In multifocal group, males with neck lymphadenectasis, ≥ 3 tumor masses or bilaterality of tumors tended to present with larger tumors, a higher incidence of neck lymph node metastasis and extra-thyroidal extension. 164 cases completed the follow-up, 5 died, 1 suspected with lung metastasis and still survived, 6 underwent repeated surgery due to lymph node recurrence at 3-41 months postoperatively and 2 surgically treated with recurrent gland tumor. Overall 1-, 2-, 5-, and 10-year survival rate was 98.2%, 97.4%, 96.5% and 96.5%, respectively. CONCLUSION Multifocal papillary thyroid carcinoma is more malignant and highly differentiated than solitary lesions. Total thyroidectomy combined with neck dissection of central compartment could be utilized as standard treatment. Lateral nodular dissection should be considered for the patients with lymph node metastasis.