MKI67 and metastatic malignant neoplasm in the lymph nodes: Variables with p < 0.1 in the univariate analysis were included in the multivariate analysis, which identified maximum tumor diameter (odds ratio [OR] = 1.012, 95% confidence interval [CI]: 1.006–1.019, p < 0.001), multifocal tumor (OR = 6.014, 95% CI: 3.164–11.431, p < 0.001), and Ki67 (OR = 1.023, 95% CI: 1.010–1.036, p < 0.001) as independent risk factors for lymph node metastasis.