Randomized Controlled Trail Of The Different Sites Of Lymph Nodes In Endobronchial Ultrasound-guided Transbronchial Needle Aspiration

Objective: This study was to compare the positive diagnostic yield and the quality of specimens that collected from different sites of lymph nodes(subcapsular or central region)by endobronchial ultrasound-guided transbronchial needle aspiration(EBUS-TBNA).Methods: 78 patients diagnosed or suspected lung cancer with mediastinal and/or hilar lymph node lesions,with a total of 96 lymph nodes,underwent EBUS-TBNA and each lymph node was sampled with 2 needle passes,respectively,from the edge(subcapsular sinus of lymph nodes)and the center of lymph nodes.A total of 192 specimens were collected.Specimens were scored cytologically using 4 parameters: amount of malignant cells,degree of cellular degeneration,retention of appropriate architecture,background blood clot.Results: Among the 96 cases of lymph nodes,79 cases of malignant lesions were diagnosed by EBUS-TBNA and the remaining which 7 cases of malignant lesions and 10 cases of benign lesions were diagnosed by other techniques.The positive diagnostic yield for EBUS-TBNA was91.9%(79/86),the subcapsular region and central region was 83.7%(72/86),68.6%(59/86),respectively,P=0.019.The score for amount of malignant cells sampled from subcapsular region of lymph nodes was1.36±0.75,which was significantly higher than the central region(1.06±0.83),P=0.013.And the degree of cellular degeneration was 1.56±0.59,1.36±0.65,respectively,sampled form the subcapsular region and the central region,P=0.038.However,there was no statistical difference in the retention of appropriate structure and background blood clot.Conclusion: In the process of diagnosis and staging of lung cancer by EBUS-TBNA,sampled form subcapsular reign of lymph node would achieve a higher positive diagnostic yield than the central region,and which would get more malignant cells and less cellular degeneration than the central region.