Thymectomy in central lymph node dissection for papillary thyroid cancer.

BACKGROUND: Central lymph node dissection (CND) has been proposed in the treatment of patients affected by papillary thyroid cancer (PTC) with clinically negative neck lymph nodes. The procedure allows pathologic staging of lymph nodes of the central compartment and treatment of the micrometastases. By comparing bilateral and unilateral thymectomy during total thyroidectomy with central lymph node dissection for postoperative complications in sonographically node-negative papillary thyroid carcinomas, we aimed to determine the optimal extent of prophylactic central lymph node dissection.

METHODS: Patients were divided into two study groups: Group 1, total thyroidectomy plus unilateral thymectomy during the CND; Group 2, total thyroidectomy associated with bilateral thymectomy (both upper poles) during the CND. Primary endpoints of the study were evaluated by comparing the postoperative complications between the two groups.

RESULTS: The only significant result found when comparing the two groups was the rate of transient hypocalcemia. (Group 1: 13.7%, Group 2: 52.4%, p<0.01). A total of five cases of papillary thymic metastases were found in this study. And final pathology confirmed that all cases of thymic metastases were lymph node micrometastases of PTC, only situated in the ipsilateral thymus upper pole.

CONCLUSIONS: Bilateral thymectomy during the CND did not provide a better carcinologic resection, as no contralateral thymic metastases were found. The unilateral thymectomy with total thyroidectomy during the CND may represent an effective strategy for reducing the rate of postoperative hypocalcemia.