Preoperative ultrasonography and serum thyroid-stimulating hormone on predicting central lymph node metastasis in thyroid nodules as or suspicious for papillary thyroid microcarcinoma.

The purpose of this study was to describe the ultrasonography (US) image features and preoperative thyroid-stimulating hormone (TSH) level in patients with thyroid nodules read as or suspicious for papillary thyroid microcarcinoma (PTMC) on US-guided fine-needle aspiration biopsy (US-FNAB) and to identify the risk factors for central lymph node metastasis (CLNM) that can guide surgical strategies for patients diagnosed with PTMC on pathology. In this retrospective cross-sectional study, a total of 163 patients diagnosed cytologically and histopathologically were included. Cytological diagnosis for each patient preoperatively was based on the Bethesda classification for the nodule: 44 (27.0 %) were suspicious for papillary carcinoma (Bethesda V) and 119 (73.0 %) were positive for papillary carcinoma (Bethesda VI). PTMC was confirmed in 162 patients on pathology. In the multivariate analysis, the US suspicious images including nodal metastases, microcalcification, and irregular margins, tumor size larger than 7 mm on US, and serum TSH level equal to or greater than 2.5 mIU/L were independent predictors for CLNM in 162 patients diagnosed with PTMC. Prophylactic central lymph node dissection (CLND) may be considered in PTMC patients presenting with risk factors.