RESUMEN
Objective To investigate the predictive factors for central lymph node metastasis (CLNM) in papillary thyroid microcarcinoma(PTMC).Methods A retrospective study including 2511 cases of PTMC admitted from Jan.2013 to Jan.2016 were enrolled in our study.Chi-square test was used in univariate analysis.Logistic regression analysis was applied for multivariate analysis.The relation between age,sex,tumor size,multifocality,thyroidal extension,nodular goiter and central lymph node metastasis is analyzed.Results Univariate analysis showed that age,sex,tumor size,multifocality,thyroidal extension and nodular goiter had statistical significance.Age less than 45(P＜0.001,x2=17.442);Male gender(P＜0.001,x2=17.029);Tumor size less than 5 mm (P＜0.001,x2=70.164.);Extrathyroid extension factor (P＜0.001,x2=63.197);Nodular hyperplasia factor (P=0.017,x2=5.611).Multivariate analysis showed there was a significant relationship between multifocality and the central lymph node positivity.The odds ratio (OR) was 1.587 in patients with tumor foci ≥2(P＜0.001).While OR increased sharply near to 3 in patients withtumor foci ≥3(OR=2.730).Tumor size(OR=1.926);Extrathyroid extension(OR=1.606).Conclusions Multifocalty,tumor size and thyroidal extension are the main predicative factors for central lymph node metastasis in PTMC.Among them,tumor foci ≥ 3 is an important predictor.Besides the conventional factors such as tumor size,thyroidal extension etc,multifocalty should also be taken into consideration.