Skip lateral neck node metastases in papillary thyroid carcinoma

Background: Papillary thyroid carcinomas (PTCs) are commonly associated with lymph node metastases (LNMs), which are thought to disseminate sequentially, first to the central compartment and later to the lateral compartment. However, a small number of patients have skip metastases to the lateral compartment without central LNMs. This study was performed to evaluate the clinicopathologic characteristics of skip metastases in PTC. Methods: We reviewed the medical records of 147 patients who underwent total thyroidectomy with central neck dissection plus modified radical neck dissection (RND) for PTC. A single surgeon performed all operations. The patients were classified as either present or absent skip metastases. The clinicopathologic characteristics were statistically analyzed. Results: Skip metastases were found in 32 patients (21.8%) and occurred commonly with primary tumors of the upper pole, and with tumors ≤1 cm in diameter. Skip metastases were less common in patients with multifocal disease. Patients with skip metastases had fewer metastatic lateral nodes that were more frequently found at a single level: mostly at level III (96.9%) and level II (34.4%). Conclusions: Although skip metastases occur in only a small number of patients, the lateral compartment should be carefully evaluated for skip metastases, even though primary tumors are either single focus, located in the upper pole, or ≤1 cm in diameter.