目的：分析超声引导下细针穿刺活检（ultrasound fine needle aspiration biopsy, US-FNAB）组织中长链非编码RNA（long non-coding RNA,lncRNA）ENST0000048967在超声诊断甲状腺乳头状癌（papillary thyroid carcinoma,PTC）淋巴结转移中的应用。方法：选取2020年6月至2020年12月于我院行US-FNAB且经手术病理证实为PTC颈部淋巴结转移的患者110例（转移组）,另设110例无颈部淋巴结转移的PTC患者作为对照（非转移组）。采用聚合酶链反应（polymerase chain reaction,PCR）检测PTC穿刺标本中ENST00000489676的相对表达水平,比较转移组与非转移组（各110例）表达水平差异,分析ENST00000489676表达水平与颈部淋巴结转移间的相关性。同时利用受试者操作特征（receiver operator characteristic,ROC）曲线计算穿刺标本ENST00000489676水平诊断PTC转移的最佳临界值（cutoff值）,计算ENST00000489676检测与超声联合诊断PTC淋巴结转移的灵敏度、特异度及准确率。结果：转移组ENST00000489676相对表达水平显著低于非转移组（2.61±1.59,3.69±2.18）（t=-4.198,P<0.001）,统计结果显示ENST00000489676低表达与PTC淋巴结转移显著相关。ROC曲线显示,ENST00000489676在穿刺标本中相对表达水平的最佳临界值为2.0950,以ENST00000489676低于该值诊断PTC淋巴结转移的灵敏度及准确率均高于超声单独诊断（灵敏度61.11%比17.27%;特异度63.39%比86.36%;准确率62.27%比51.82%）。结论：低表达ENST00000489676与PTC淋巴结转移显著相关,ENST00000489676作为分子标志物可应用于辅助超声诊断。

Objective: To analyze the value of lncRNA ENST0000048967 detection in biopsy tissue of papillary thyroid carcinoma (PTC) by ultrasound-guided fine-needle aspiration (US-FNA) for diagnosing cervical lymph node metastasis. Methods: A total of 110 PTC patients with pathologically confirmed cervical lymph node metastasis in Ruijin hospital during June 2020 to December 2020, were enrolled (study group). Another 110 PTC patients without cervical lymph node metastasis were served as the control group. The expression level of ENST00000489676 in FNA biopsy samples from 220 patients were detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The correlation of ENST00000489676 expression with lymph node metastasis in PTC patients was explored. ROC curve was used to calculate the cutoff value of ENST00000489676 expression level for diagnosing cervical lymph node metastasis of PTC in puncture specimens. The sensitivity, specificity and accuracy of ultrasonography alone and combined with ENST00000489676 detection in FNA biopsy samples for diagnosis of lymph node metastasis were also calculated respectively. Results: The expression of ENST0000048967 in study group was significantly lower than that in non-lymph node metastasis group(t=-4.198, P<0.001). The statistical results showed that the low expression of ENST000000489676 was positively correlated with PTC lymph node metastasis. The optimal cutoff value of ENST00000489676 for diagnosing cervical lymph node metastasis of PTC in the FNAB specimen was 2.0950 by ROC curve. The sensitivity and accuracy of ultrasonography combined with ENST00000489676 detection for diagnosising lymph node metastasis were higher than those of ultrasonography alone, respectively(sensitivity, 61.11% and 17.27%; specificity, 63.39% and 86.36%; accuracy, 62.27%, and 51.82%). Conclusions: Low expression of ENST00000489676 is significantly correlated with lymph node metastasis of PTC. ENST00000489676 may serve as a molecular marker to assist ultrasonography diagnosis of cervical lymph node metastasis for PTC.