Conventional Ultrasound, Immunohistochemical Factors and BRAFV600E Mutation in Predicting Central Cervical Lymph Node Metastasis of Papillary Thyroid Carcinoma

The study was aimed at evaluating the correlation between central cervical lymph node metastasis (CLNM) in papillary thyroid carcinoma (PTC) patients and ultrasound (US) features, immunohistochemical factors and BRAFV600E mutation. A total of 225 consecutive patients (225 PTCs) who had undergone surgery were included. All PTCs were pre-operatively analysed by US with respect to size, components, echogenicity, shape, margins, microcalcification, multiple cancers or not, internal vascularity and capsule contact or involvement. The presence of four immunohistochemical factors, including cytokeratin 19, human bone marrow endothelial cell 1, galectin-3 and thyroid peroxidase, and BRAFV600E mutation was also evaluated. Univariate and multivariate analyses were performed to identify the risk factors for central CLNM, and a risk model was established. Pathologically, 44% (99/225) of the PTCs had central CLNMs. Multivariate analysis revealed that size ≤10mm, microcalcification, internal vascularity, capsule contact or involvement and BRAFV600E mutation were independent risk factors for central CLNM. The risk score for central CLNM was calculated as follows: risk score = 1.5 × (if lesion size ≤10 mm) + 1.9 × (if microcalcification) + 0.8 × (if internal flow) + 3.0 × (if capsule contact or involvement) + 1.5 × (if BRAFV600E mutation). The rating result was divided into six stages, and the relevant risk rates of central CLNM were 0% (0/1), 0% (0/22), 7.4% (4/54), 48.6% (34/70), 71.2% (42/59) and 100% (19/19), respectively. In conclusion, PTC ≤10mm, microcalcification, internal vascularity, capsule contact or involvement and BRAFV600E mutation are risk factors for central CLNM. The risk model may be useful in treatment planning and management of patients with PTCs.