https://www.selleckchem.com/JAK.html 3% in the 30 nodules with final diagnoses and 18.4% in all nodules. Among the six surgically-treated malignant tumors, five (83.3%) had an extrathyroidal extension (ETE) (minor ETE 1, gross ETE 4), and two (33.3%) had macroscopic lymph node metastasis. Four (66.7%) malignant tumors were categorized as high-risk tumors, one as an intermediate-risk tumor, and one as a low-risk tumor using the ATA risk stratification. Histopathologically, out of the six malignant tumors, ossifications were noted in four (66.7%) and predominant calcifications in two (33.3%). CONCLUSION The US pattern of isolated macrocalcifications (≥ 1 cm) showed an intermediate malignancy risk (at least 18.4%). All malignant tumors were PTCs, and most showed an aggressive behavior and a high or intermediate postoperative ATA risk. Copyright © 2020 The Korean Society of Radiology.OBJECTIVE Proper management of lymph nodes (LNs) with ultrasonographic (US) indeterminate features in thyroid cancer patients remains elusive. We aimed to evaluate the malignancy risk and US findings predictive of malignancy for US indeterminate LNs in preoperative thyroid cancer patients through node-by-node correlation. MATERIALS AND METHODS A total of 348 LNs in 284 thyroid cancer patients, who underwent fine-needle aspiration or core-needle biopsy between December 2006 and June 2015, were included. We determined the malignancy risks for US probably benign, indeterminate, and suspicious categories. For US indeterminate LNs, which had neither echogenic hilum nor hilar vascularity in the absence of any suspicious finding, US findings were compared between benign and metastatic LNs using Mann-Whitney U test and Fisher's exact test. RESULTS US imaging diagnoses were probably benign in 20.7% (n = 72) cases, indeterminate in 23.6% (n = 82), and suspicious in 55.7% (n = 194). Malignancy risk of US indeterminate LNs (19.5% [16/82]) differed from those of the US probably benign (2.8% [2/72]) (p =