Risk factors of central lymph node metastasis in patients with papillary thyroid microcarcinoma

Objective To analyze the clinical characteristics of patients with papillary thyroid microcarcinoma (PTMC), and explore risk factors of central lymph node metastasis (CLNM)in patients with PTMC. Methods A total of 254 patients with PTMC from January, 2013 to June, 2016 were analyzed retrospectively, all subjects underwent central compartment lymph node dissection. The patients were assigned into positive group and negative group according to the CLNM. The risk factors for CLNM were analyzed with respect to sex, age, tumor size, tumor multifocal, microcalcification, lymphadenectasis of lateral neck. Results Among the 254 patients, the CLNM occurred in 77 patients (30.3%). The univariate analyses showed that gender of male, age of <45 years, tumor diameter ≥ 5 mm, multifocality and lymphadenectasis of lateral neck significantly increased the risk of CLNM (all P<0.05). Nevertheless, the microcalcification was not significantly related to the presence of CLNM (P>0.05). Multivariate analysis showed that gender of male, tumor diameter ≥ 5 mm multifocality, and lymphadenectasis of lateral neck were independent risk factors for central lymph node metastasis (all P<0.05). Conclusion The gender of male, age of <45 year, tumor diameter ≥ 5 mm, multifocality and lymphadenectasis of lateral neck are associated with CLNM in PTMC patients. The male patients with primary lesions ≥ 5 mm in diameter, multiple lesions and preoperative ultrasound findings of cervical lymphadenopathy are the independent risk factors for CLNM in patients with PTMC.