EUS-guided tissue acquisition in the study of the adrenal glands: Results of a nationwide multicenter study

BackgroundThere are limited data about the role of endoscopic ultrasound-guided tissue acquisition (EUS-TA), by fine needle aspiration (EUS-FNA) or biopsy (EUS-FNB), in the evaluation of the adrenal glands (AG). The primary aim was to assess the diagnostic yield and safety. The secondary aims were the malignancy predictors, and to create a predictive model of malignancy.MethodsThis was a retrospective nationwide study involving all Spanish hospitals experienced in EUS-TA of AGs. Inclusion period was from April-2003 to April-2016. Inclusion criteria: all consecutive cases that underwent EUS-TA of AGs. EUS and cytopathology findings were evaluated. Statistical analyses: diagnostic accuracy of echoendoscopist’s suspicion using cytology by EUS-TA, as gold standard; multivariate logistic regression model to predict tumor malignancy.ResultsA total of 204 EUS-TA of AGs were evaluated. Primary tumor locations were lung70%, others19%, and unknown11%. AG samples were adequate for cytological diagnosis in 91%, and confirmed malignancy in 60%. Diagnostic accuracy of the endosonographer's suspicion was 68%.The most common technique was: a 22-G (65%) and cytological needle (75%) with suction-syringe (66%). No serious adverse events were described. The variables most associated with malignancy were size>30mm (OR2.27; 95%CI, 1.16–4.05), heterogeneous echo-pattern (OR2.11; 95%CI, 1.1–3.9), variegated AG shape (OR2.46; 95%CI, 1–6.24), and endosonographer suspicion (OR17.46; 95%CI, 6.2–58.5). The best variables for a predictive multivariate logistic model of malignancy were age, sex, echo-pattern, and AG-shape.ConclusionsEUS-TA of the AGs is a safe, minimally invasive procedure, allowing an excellent diagnostic yield. These results suggest the possibility of developing a pre-EUS procedure predictive malignancy model.

**背景** 目前关于内镜超声引导下组织获取术（endoscopic ultrasound-guided tissue acquisition, EUS-TA）——包括细针抽吸术（fine needle aspiration, EUS-FNA）与细针活检术（fine needle biopsy, EUS-FNB）——在肾上腺（adrenal glands, AG）评估中的应用价值，相关研究数据较为匮乏。本研究的首要目标为评估该术式的诊断效能与安全性；次要目标为探索恶性病变的预测因子，并构建恶性病变预测模型。

**方法** 本研究为一项回顾性全国多中心研究，纳入所有具备肾上腺EUS-TA操作经验的西班牙医院。研究纳入时段为2003年4月至2016年4月，纳入标准为所有接受肾上腺EUS-TA的连续病例。本研究对内镜超声检查结果与细胞病理学结果进行评估，统计分析内容包括：以EUS-TA获取的细胞学标本作为金标准，评估内镜超声医师预判结果的诊断准确率；构建用于预测肿瘤恶性程度的多因素logistic回归模型。

**结果** 本研究共纳入204例肾上腺EUS-TA病例进行分析。原发肿瘤的部位分布为：肺部来源占70%，其他来源占19%，来源未知占11%。91%的肾上腺标本可满足细胞病理学诊断要求，其中60%经病理证实为恶性病变。内镜超声医师的预判诊断准确率为68%。本研究最常采用的操作技术为：22G穿刺针（占65%）、细胞学专用穿刺针（占75%）配合负压抽吸装置（占66%）。本研究未报告严重不良事件。与恶性病变相关性最强的变量包括：病灶直径>30mm（优势比OR=2.27，95%置信区间CI：1.16~4.05）、回声模式不均质（OR=2.11，95%CI：1.1~3.9）、肾上腺形态斑驳不均（OR=2.46，95%CI：1~6.24）以及内镜超声医师的恶性预判结果（OR=17.46，95%CI：6.2~58.5）。用于构建恶性病变预测多因素logistic回归模型的最优变量为患者年龄、性别、回声模式以及肾上腺形态。

**结论** 肾上腺EUS-TA是一种安全、微创的操作方式，可获得优异的诊断效能。本研究结果提示，可进一步开发用于术前预判肾上腺病变恶性程度的预测模型。