Diagnostic Yield of Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration Cytological Smears and Cell Blocks: A Single-Institution Experience

Abstract

Background and Objective: Endobronchial ultrasound (EBUS) is a minimally invasive endobronchial technique, which uses ultrasound along with a bronchoscope to visualize the airway wall and structures that are adjacent to it. Indications for endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) are samplings of mediastinal, hilar lymph nodes, and tumors adjacent to airway walls. EBUS-TBNA has been used in our clinic since 2009. The aim of the study is to evaluate the sensitivity, specificity, positive and negative predictive value, and diagnostic accuracy of cytological and histological specimens, and the safety of EBUS-TBNA in an unselected patient population that has been referred to our hospital. Materials and Methods: We have retrospectively analyzed the medical documentation of 215 patients who had EBUS-TBNA performed in our clinic from April 2009 to February 2014. Results: There were 215 patients who underwent EBUS-TBNA. A total of 296 lymph nodes were sampled. EBUS-TBNA was diagnostic in 176 (81.9%) cases of cytological, 147 (68.4%) cases of histological, and 191 (88.9%) cases of the combined evaluation. In the lung cancer patients, EBUS-TBNA cytology had a sensitivity of 72.9% and histology of 72.9%, and in the sarcoidosis group, it had a cytology of 55.8% and histology of 64.5%. As all positive cytology and histology specimens were assumed to be true positive, specificity and positive predictive value (PPV) were 100%. The sensitivity and diagnostic accuracy was significantly higher when cytology and histology specimens were combined, compared with cytology or histology results evaluated separately (p < 0.05) (for lung cancer 84.1% and for sarcoidosis 78.8%). The sensitivity and diagnostic accuracy of EBUS-TBNA procedures increased significantly over time, with increased experience. There were no complications with EBUS-TBNA in our clinical practice. Conclusions: EBUS-TBNA had a high diagnostic yield and was safe in the diagnosis of lung cancer and sarcoidosis. It was most informative when cytology and histology were combined. The informative value of EBUS-TBNA histology increased with our experience.