Predicting factors for lateral lymph node metastasis in papillary thyroid microcarcinoma

Abstract

Objective To determine the predictive factors for lateral lymph node metastasis (LNM) in papillary thyroid microcarcinoma (PTMC). Methods From January 2002 to December 2009,77 patients with PTMC were treated by modified radical neck dissection. We analyzed the association between lateral LNM and clinical factors, US features, hematological parameters and pathologic features of PTMC. Results The rate of lateral LNM was 39% in 77 PTMCs (30/77). We found a statistically significant association between lateral LNM and age, pathologic features ( extrathyroid invasion and central LNM), higher platelet counts and US features of PTMC (upper pole location,contacting area of the tumor with the capsule of throid gland > 25% of the perimeter of the tumor) in univariate analysis (statistic values were 2.425,6. 392,12. 584,2. 143,8.755 and 6.89,respectively,Ps< 0.05). Age,pathologic features (central LNM) and US features of PTMC (upper pole location) were found to be independent predictive factors for lateral LNM in multivariate analysis ( OR and 95%C/ was 0.942(0.889 -0.998) ,4. 396( 1. 241 - 15. 573) and 4.436( 1. 194 - 16. 482) ,P was 0. 042, 0.022 and 0.026,respectively). Conclusion In patients with PTMC,independent factors in predicting lateral LNM were age, US features of PTMC ( upper pole location) and pathologic features (central LNM ). These patients should receive relatively aggressive initial treatments and vigilant follow-up. Key words: Thyroid neoplasms; Papillary thyroid microcarcinoma; Lymphatic metastasis