细针抽吸物（FNA-Tg）中甲状腺球蛋白的测量有助于诊断甲状腺癌淋巴结转移；然而，截止值仍不清楚，特别是对于颈部肿块的鉴别诊断。为了评估FNA-Tg的临界值，我们对2015年10月至2020年9月在我院术前接受FNAC和FNA-Tg并进行病理检查的甲状腺外颈部肿块患者进行了回顾性研究。 FNA-Tg值通过受试者工作特征曲线计算。在210个病灶中，57个病灶是甲状腺起源的，153个病灶不是甲状腺起源的。在甲状腺来源的病变中观察到较高的 FNA-Tg 值 (p:0.001)，100% 特异性的最低点截止值为 32.2 ng/ml，敏感性为 87.7%。关于血清抗Tg抗体的作用，FNA-Tg值根据分组显着降低或没有显着差异，需要进一步研究。在甲状腺乳头状癌病例中，FNAC和FNA-Tg的敏感性分别为71.4%和87.5%。 FNA-Tg鉴别诊断颈部肿块的临界值较以往报道较高，因为除淋巴结外，部分癌及病灶转移淋巴结的FNA-Tg值较高。因此，如果要将FNA-Tg用作未确诊甲状腺癌患者颈部肿块鉴别诊断的筛查试验，则有必要建立更高的截止值。

Measurement of thyroglobulin in fine needle aspirates (FNA-Tg) is useful for the diagnosis of lymph node metastasis in thyroid carcinoma; however, the cutoff value remains unclear, particularly for the differential diagnosis of neck masses. To evaluate cutoff value of FNA-Tg, we conducted a retrospective study of patients with neck masses outside the thyroid which are pre-operatively underwent both FNAC and FNA-Tg followed by pathological examination at our hospital from October 2015 to September 2020. The cutoff value of FNA-Tg was calculated by the receiver operating characteristic curve. Among 210 lesions, 57 were of thyroid origin and 153 lesions were not thyroid origin. High FNA-Tg value was observed in the lesions with thyroid origin (p:0.001) and the cutoff value at the minimum point of 100% specificity was 32.2 ng/ml and the sensitivity was 87.7%. Regarding the effect of serum anti-Tg antibodies, FNA-Tg values were significantly lower or not significantly different depending on the grouping, and further studies are needed. Among the cases with papillary thyroid carcinoma, the sensitivity of FNAC and FNA-Tg was 71.4% and 87.5%, respectively. The cutoff value of FNA-Tg for the differential diagnosis of neck masses was higher compared with that of previous reports because some metastatic lymph nodes of carcinomas and lesions, other than lymph nodes, exhibited higher FNA-Tg values. Therefore, if FNA-Tg is to be used as a screening test for the differential diagnosis of neck masses in patients without proven thyroid carcinoma, it is necessary to establish a higher cutoff value.