Pattern of nodal metastasis for primary and reoperative thyroid cancer.

This retrospective investigation was undertaken to clarify the pattern of nodal metastasis in papillary (PTC) and medullary (MTC) thyroid carcinoma. Nodal metastases are associated with recurrence of both PTCs and MTCs. The extent of lymph node dissection is controversial owing to the lack of reliable diagnostic criteria for nodal metastases other than histopathology. Between November 1994 and October 1999 a total of 296 patients (134 PTCs, 162 MTCs) underwent total thyroidectomy in conjunction with a standard resection of at least the cervicocentral lymph node compartment. Of 10,446 sampled lymph nodes, 1641 were positive. All nodes were related to their respective cervicomediastinal compartments. The ipsilateral cervicolateral compartment was involved almost as often as the cervicocentral compartment in primary PTC (29% vs. 32%), reoperative PTC (21% vs. 37%), primary MTC (34% vs. 34%), and reoperative MTC (49% vs. 65%). The contralateral cervicolateral and mediastinal compartments were more rarely affected, and were least affected in the primary setting. From these data was derived an individualized surgical strategy for PTC and MTC. This concept rests on the joint resection of cervicocentral and ipsilateral cervicolateral compartments. Depending on tumor entity, surgical status, and primary tumor diameter, additional compartments may have to be cleared.