[Clinical analysis of level II occult metastasis of papillary thyroid carcinoma].

OBJECTIVE

To analyze the relevant factors occult II lymph node metastases in papillary thyroid carcinoma (PTC) with clinical factors.

METHODS

The medical records of 213 PTC patients with clinically positive neck lymph nodes in level III and IV, and/or V based on preoperative ultrasonography, treated between January 2003 and December 2009 were retrospectively reviewed. All patients had no suspicion of clinical positive neck nodes in level II. Univariate and Multivariate analysis were performed using the Pearson chi-square test or Fisher's exact test and a binary logistic regression test, respectively.

RESULTS

The rate of metastasis at levels III, IV, V and VI was 83.6% (178/213), 75.1% (160/213), 13.1% (28/213) and 79.3% (169/213), respectively. The rate of occult metastasis at level II were observed in 16.0% (34/213). In univariate analysis, lymph node metastasis in level II was statistically significantly more frequent in patients with positive level III lymph node and positive lymph node throughout the lateral neck (level III + IV, χ(2) were 11.120 and 5.614 respectively, P < 0.05). Multivariate analysis showed that positive lymph node involvement in all lateral neck (level III + IV) was an independent predictive factor of level II lymph node metastasis (P = 0.033, OR = 3.846).

CONCLUSION

In PTC patients without suspicious lymph node in neck level II and III by preoperative US, prophylactic level II lymph node dissection may not be considered.