NIFT-P（非侵袭性滤泡甲状腺肿瘤伴类乳头状核特征）是滤泡型甲状腺乳头状癌（PTC）的封闭性变异，具有非侵袭性临床特点。然而，由于它的诊断只能在手术后进行，因此它代表了临床上的挑战。颈部超声（US）在提示甲状腺结节的恶性可能性方面具有较好的敏感性和特异性。然而，关于其在鉴别NIFT-P中的能力的信息很少。本研究旨在评估NIFT-P的超声特征，将其与其他滤泡样甲状腺肿瘤进行比较，并测试主要的US风险分层系统（RSS）在识别NIFT-P方面的能力。我们回顾性评估了403例接受甲状腺手术的连续患者，至少有一个结节的组织学结果为NIFT-P、PTC滤泡变异、滤泡状甲状腺癌或滤泡腺瘤。报道了NIFT-P（n=116）、PTC滤泡变异（n=170）、滤泡状甲状腺癌（n=76）和滤泡腺瘤（n=90）的超声特征。与NIFT-P相比，PTC滤泡变异和滤泡状甲状腺癌更常见于不规则边缘、钙化物的存在、"高大于宽"的形状，并缺乏光环。此外，滤泡状甲状腺癌但也包括滤泡腺瘤比NIFT-P更大，更常见于低回声。大多数病例（77%）显示为不确定的细胞学。无论考虑哪种US风险分层系统，与PTC滤泡变异和滤泡状甲状腺癌相比，NIFT-P和滤泡腺瘤较少被分类在高疑似类别中。NIFT-P的超声特征经常与低疑似恶性结节相似。根据主要的US风险分层系统，NIFT-P几乎从不被分类为高疑似类别。因此，尽管NIFT-P的术前识别仍然具有挑战性，但颈部超声可以在不确定细胞学结节的管理算法中加以整合，为那些具有低疑似特征的患者提供可能的保守治疗方法。© 作者2023年发表。由牛津大学出版社代表欧洲内分泌学学会（European Society of Endocrinology）的版权所有。保留所有权利。有关权限，请发送电子邮件至：journals.permissions@oup.com。

NIFT-P (non-invasive follicular thyroid neoplasm with papillary-like nuclear features) is an encapsulated follicular variant of papillary thyroid carcinoma (PTC) with non-aggressive clinical behavior. However, since its diagnosis is exclusively possible after surgery, it represents a clinical challenge. Neck ultrasound (US) shows good sensitivity and specificity in suggesting malignancy in thyroid nodules. However, few information is available about its ability in identifying NIFT-P.The aim of this study was to evaluate the US features of NIFT-P, comparing them with other follicular patterned thyroid tumors, and to test the ability of the main US risk stratification system (RSS) in identifying NIFT-P.We retrospectively evaluated 403 consecutive patients submitted to thyroid surgery, with positive histology for at least one nodule being NIFT-P, follicular variant of PTC (FV-PTC), follicular thyroid carcinoma (FTC) or follicular adenoma (FA).The US features of NIFT-P (n=116), FV-PTC (n=170), FTC (n=76) and FA (n=90) were reported. FV-PTC and FTC more frequently showed irregular margins, presence of calcifications, "taller than wide" shape, and the absence of halo compared to NIFT-P. Furthermore, FTC but also FA were larger and more frequently hypoechoic than NIFT-P. Most cases (77%) showed an indeterminate cytology. Regardless of the US RSS considered, NIFT-P and FA were less frequently classified in the high-suspicious category compared to FV-PTC and FTC.US features of NIFT-P are frequently superimposable to those of nodules with low-suspicious of malignancy. NIFT-P is almost never classified in the high-suspicious category according to the main US RSS. Therefore, although the pre-operative identification of NIFT-P remains a challenge, neck US can be integrated in the algorithm of management of nodules with indeterminate cytology, suggesting a possible conservative approach in those with low-suspicious features.© The Author(s) 2023. Published by Oxford University Press on behalf of European Society of Endocrinology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.