Risk factors for predicting central lymph node metastasis in papillary thyroid microcarcinoma.

Objective: We aimed to determine the predictive factors for central compartment lymph node metastasis (LNM) in papillary thyroid microcarcinoma (PTMC). The outcome of the current study could assist greatly in decision-making regarding further treatment.

Methods: Retrospective analysis of PTMC treated at the First Affiliated Hospital of Harbin Medical University. The predictive risk factors for central lymph node metastases (CLNM) were analyzed with respect to age, sex, tumor size, multifocal and capsular affection.

Results: CLNM are common in thyroid microcarcinoma patients. The factors correlated with neoplasm size greater than 5 mm (odds ratio, 0.520; P = 0.001), tumor bilateral (odds ratio, 0.342; P = 0.020), and capsule invasion (odds ratio, 2.539; P = 0.000) were independently predictive of CLNM. In patients with a solitary primary tumor, tumor location in the lower third of the thyroid lobe was associated with a higher risk of CLNM.

Conclusions: The risk factors such as male gender, tumor size > 5 mm, bilateral, multifocal location, lower third of the thyroid lobe and capsule invasion that can be identified preoperatively or intraoperatively, be considered for determination of prophylactic CLND in patients with PTMC.