Central compartment lymph node metastasis in cNO papillary thyroid carcinoma

Objective To evaluate the incidence and the predictive factors for the metastasis of central compartment lymph nodes （ level Ⅵ ） in clinically node-negative （cNO） papillary thyroid carcinoma （PTC）. Methods One hundred and eight patients with cNO PTC underwent neck dissection for level Ⅵ between January 2003 and December 2006 were followed up and analyzed retrospectively. Univariate analysis with the x2 test was used to analyze the statistical correlation between central compartment lymph nodes metastasis and the other clinical factors. Multiple Logistic regression analysis was used to identify the multivariate correlates of central compartment metastasis. Kaplan-Meier method was used to calculate the accumulative survival rate, lateral neck recurrence and metastasis rate. Results Metastasis rate in level Ⅵ was 59. 2% （64/108）. Age below 45, tumor size > 3 cm and extracapsular spread were independent predictive factors for the metastasis in level Ⅵ （odds ratio were 5.514, 5.610 and 3. 122, P < 0. 05,respectively）. There were low incidence of postoperative complications, 2 cases with transient nerve palsy （1. 8%）, 5 cases with transient hypoparathyroidism （4. 6%） and 1 case with permanent hypoparathyroidism（0.9% ）. Six cases with ipsilateral neck recurrence, 1 case died. The 5-year lateral neck recurrence rate and accumulative survival rate were 4. 8% and 99. 1% respectively. Conclusion Metastasis in level Ⅵ in the patients with cNO PTC is common and selective neck dissection is necessary for the patients. Key words: Thyroid neoplasms; Carcinoma, papillary; Lymphatic metastasis; Radical neckdissection