[Predictive factors for level VI lymph node metastasis in papillary thyroid microcarcinoma].

Objective: To determine the predictive factors for level VI lymph node (LN) metastasis in thyroid papillary microcarcinoma (PTMC).

Methods: From November 2005 to January 2007, 86 patients with PTMC with a lateral cN0 were treated by thyroidectomy and elective level VI LN dissection without comprehensive lateral neck dissection. The data from the cases were analyzed retrospectively to determine the predictive factors for level VI LN metastasis.

Results: Forty cases (46.5%) of the patients were found with level VI LN metastasis. Tumor size (> or = 5 mm), thyroid capsular invasion or extracapsular invasion, enlarged level VI LN size (> or = 4 mm) were found significantly related to level VI LN metastasis on univariate analysis (P < 0.05). Tumor size (> or = 5 mm) and thyroid capsular invasion or extracapsular invasion were found to be independent predictive factors for level VI LN metastasis on multivariate analysis (P < 0.05).

Conclusions: Thyroid capsular invasion or extracapsular invasion, tumor size (> or = 5 mm) were significantly associated with level VI LN metastasis in patients with PTMC. Elective neck dissection in level VI should be considered particularly in patients with thyroid capsular invasion or extracapsular invasion and a tumor greater than 5 mm.