RESUMEN
Objective To investigate the related factors of central regional lymph node metastasis (CLNM) in patients with papillary thyroid microcarcinoma (PTMC).Methods The clinical and pathological fea tures of 550 cases of PTMC with clinical lymph node negative (cN0) were retrospectively analyzed.x2 test and multivariate logistic regression analysis were used to analyze the related factors of CLNM.ROC curve was used to analyze tumor diameter and CLNM of PTMC.Results The CLNM rate was 35.6％.Univariate analysis showed that patients aging less than 45 y(x2=13.983,P＜0.001),with tumor diameter≥7 mm (x2=14.263,P＜0.001),with capsule invasion (x2=7.316,P=0.006),multifocality (x2=14.321,P＜0.05) and bilateral tumors (x2=9.265,P=0.002) were more likely to have CLNM.Multivariate Logistic regression analysis showed that age ＜45 y,tumor diameter ≥7 mm,invasion of capsule and multifocal are all independent risk factors of CLNM for patients with PTMC.The optimal cutoff value of CLNM by diameter was 8 mm.Conclusion The CLNM of PTMC is related to many factors.When the age of the patient is less than 45 y,the diameter of the tumor is more than 7 mm,the invasion of the capsule and the multifocal lesion,the central lymph node dissection should be performed.