超声支气管镜检查对纵隔肿大淋巴结诊断意义及假阴性分析

Value of endobronchial ultrasound-guided transbronchial needle aspiration of enlarged mediastinal lymph nodes and analysis of false negative results

目的探讨超声支气管镜引导下针吸活检（EBUS-TBNA）对纵隔肿大淋巴结的诊断意义及其诊断假阴性的原因。方法回顾性分析2009年10月至2015年10月就诊于山东省肿瘤医院，影像学检查显示纵隔淋巴结肿大，而常规支气管镜检查未发现病变的389例患者的临床资料，评价EBUS-TBNA在纵隔淋巴结肿大诊断中的意义，并分析其假阴性原因。结果389例患者中，穿刺阳性362例，穿刺阴性27例。EBUS-TBNA的敏感度、特异度、阳性预测值及阴性预测值分别为92．9％、100％、100％和25．0％。EBUS．TBNA穿刺的阳性率与淋巴结直径有关（P=0．021）。淋巴结穿刺阳性率最高为隆突下淋巴结（97．7％），其次为气管旁淋巴结（91．2％），差异有统计学意义（P=0．006）。EBUS-TBNA穿刺的阳性率与病理类型无关（P=0．932）。细胞学和病理学诊断淋巴结的阳性率分别为88．7％和92．5％，差异无统计学意义（P=0．065）。穿刺针型号（分别为21G和22G）对病变诊断准确性差异无统计学意义（P=0．142）。随着穿刺病例增加，操作者熟练程度和技术的提高，经验的积累，获得标本的比例和质量都随之升高，穿刺病理和细胞学阳性率有明显提高。结论EBUS-TBNA具有微创、局麻、安全和可重复性等特点，为肿大纵隔淋巴结明确诊断及评估肿瘤分期的实用性技术，具有独特的临床应用价值。积累操作经验、提高操作技术、与病理科和细胞室医师紧密合作，可进一步减少假阴性的发生．提高EBUS-TBNA的阳性率。

Objective To explore the diagnostic value of endobronchial ultrasound-guided transbronchial needle aspiration （EBUS-TBNA） in the diagnosis of enlarged mediastinal lymph nodes, and to analyze the reasons of false negative results of EBUS-TBNA. Methods A retrospective analysis of the clinical and imaging data of 389 patients who underwent EBUS-TBNA for sampling enlarged hilar and mediastinal lymph nodes from October 2009 to October 2015 in Shandong Tumor Hospital, to evaluate its significance in the diagnosis of enlarged mediastinal lymph nodes, and to analyze the reasons of false negative results. Results Among the 389 collected cases, positive biopsy results were obtained in 362 cases, and false negative results in 27 cases. The sensitivity, specificity, positive predictive value and negative predictive value were 92.9%, 100%, 100% and 25.0%, respectively. There was a positive correlation between the size of lymph node and biopsy positive rate （P= 0.021 ）. The subcarinal lymph nodes had the highest positive rate （97.7%） , followed by the paratracheal lymph nodes （91.2%） , with a statistically significant difference （P=0.006）. The positive rates obtained by cytology （88.7%） and pathology （92.5%,） showed no significant difference （ P = 0.065）. The positive rate of EBUS-TBNA was not correlated with pathological types （P= 0.932）. Needle types （21G, 22G） had no significant effect on diagnosis accuracy （P = 0. 142）. Conclusions EBUS-TBNA is a practical technology for diagnosis of enlarged mediastinal lymph nodes, with unique characteristics such as minimally iuvasiveness, local anesthesia, good safety andrepeatability. Along with the accumulation of surgical experience, improvement of operative skills, more close cooperation between surgeons, cytologists and pathologists, false negative results will be reduced and positive rate of EBUS-TBNA examination will be further improved.