Experience and analysis of level VII cervical lymph node metastases in patients with papillary thyroid carcinoma

PURPOSE: Papillary thyroid cancer with level VII (anterior superior mediastinal lymph nodes) lymph node metastasis belongs to Stage IV a according to the Americal Joint Committee on Cancer cancer staging. The aim of our study was to identify clinicopathologic factors that are related to level VII cervical lymph node metastasis and to suggest recommendations for level VII dissection. METHODS: We reviewed 195 patients with papillary thyroid carcinoma who had their initial operation containing level VII dissection from April 2006 to June 2007. Level VII dissection involved lymph nodes in the anterior superior mediastinum and tracheoesophageal grooves, extending from the suprasternal notch to the innominate artery. Clinicophathologic factors, such as gender, age and lateral neck metastasis, related to Level VII metastasis were analyzed by tumor size, multifocality of tumor, extrathyroidal extension and lymphovascular invasion. RESULTS: Nine (4.6%) of 195 patients with papillary thyroid carcinoma had level VII metastasis. Clinicopathologic factors that were related to level VII metastasis included lateral neck metastasis (P < 0.01), tumor size (P < 0.01) and lymphovascular invasion (P < 0.05). CONCLUSION: If preoperatively, the tumor size is over 1.5 cm, or there is lateral neck metastasis, level VII dissection must be considered. If there is lymphovascular invasion pathologic findings postoperatively, special attention should be paid for detection of level VII recurrence.