A Practical Alternative Approach to Rapid Cytological Analysis for Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration at Community Hospitals: A Retrospective Study with Cytologic-Histologic Correlation

Summary: Introduction: Endobronchial ultrasound–guided transbronchial needle aspiration (EBUS-TBNA) is the most commonly used approach for diagnosing and staging lung cancers with several advantages including minimally invasive approach, safe, cost-effective, real time image guidance, broad sampling capability, and rapid on-site evaluation (ROSE). However, utility of ROSE during EBUS-TBNA has been matter of debate, in terms of diagnostic efficacy. We employed a method for performing EBUS without ROSE at our institution with staffing and cost benefit. We're a tertiary care center with a main campus and peripheral sites. This study was focused on EBUS performed at peripheral sites. Materials and Methods: EBUS specimens from all passes were fixed in Saccomanno, the sediment was used to prepare a cell block, the supernatant was used to prepare one ThinPrep slide for cytologic evaluation. We reviewed the cytological profile of 96 patients in a period of three months, including 31 lymph node only cases, 20 lung only cases, and 45 cases of both lymph node and lung sampling. Our aims:1) Compare the non-diagnostic rates between our method with the EBUS+ROSE method. 2) Establish sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of our method and compare with EBUS+ROSE method. Results: Of cases of 140 lymph node sampling, 34 nodes (24.3%) were diagnosed as malignant, 82 nodes (58.6%) as benign, and 3 nodes (2.1%) as atypical. Of the 70 cases of lung lesion sampling, 22 cases (31.4%) were diagnosed as malignant, 17 cases (24.3%) as benign process, and 5 cases (7.1%) as atypical cells. The lymph node nondiagnostic rate was 15% (21 nodes), whereas the nondiagnostic rate for lung lesions (26 cases) was 37.1%. 25 of 26 lung cases with non-diagnostic FNAs had concurrent core biopsies; 13 were non-diagnostic, 20 were benign, and 2 were malignant on histology. 5 atypical lung cases included 1 carcinoid tumor and 1 eventually proven to be adenocarcinoma on subsequent resection. 72 patients had corresponding core biopsies or follow-up surgery. When histology was taken as the gold standard, the sensitivity, specificity, and positive and negative predictive values for EBUS-TBNA were 86.4%, 97.9%, and 95% and 94%, respectively. Two had positive FNAs and negative core biopsies. Conclusions: Although ROSE has been successfully introduced into daily clinical practice at hospitals, considering the cost, staffing issues, and the distance between different sites, we used an alternative method which does not utilize ROSE but is time saving, cost effective, and felt to be comparable in terms of performance at community hospitals/ peripheral sites.