The qualitative role of Endobronchial Elastography with Endobronchial Ultrasound in differentiating Malignant and Benign lesions-A retrospective single center study

Introduction: The aim of this study was to evaluate the usefulness of EBUS elastography for mediastinal lymph nodes by comparing the elastographic patterns of lymph nodes with the final pathological diagnosis from EBUS-guided transbronchial needle aspiration. Methods: The convex probe EBUS was inserted through the oral route, and images were generated using a dedicated processor to assess elastographic patterns that were classified based on color distribution-Type-1, predominantly non-blue (green, yellow and red);Type-2-less than 50% blue, part non-blue(green, yellow and red);Type-3-predominant blue color. The elastographic patterns were compared with the final pathologic diagnosis results Results: On evaluating the cell blocks,40 were benign and 18 were malignant. Nodes that were assigned as Type-1 were benign in 18/18 (100%); for Type-2 lymph nodes, 16/22 (72.7%) were benign and 6/22 (27.27%) were malignant; Type-3 lymph nodes were benign in 6/18 (33.33%) and malignant in 12/18 (66.66%). On classifying Type 3 as ‘malignant’ and Type 1 as ‘benign,’ the sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy rates were 100%, 75%, 66%, 100% and 83.3%, respectively. Conclusion: Endobronchial ultrasound elastography of mediastinal lymph nodes is a relatively new noninvasive technique that may be helpful in the prediction of nodal characteristics and in selecting sites for biospy during EBUS guided transbronchial needle aspiration