Endobronchial ultrasound guided transbronchial needle aspiration cytology and cellblock in evaluation of mediastinal lymphadenopathy in adults – An initial experience from Eastern India

Abstract

Introduction: Additional yield of Cell block over cytology in endobronchial ultrasound guided transbronchial needle aspiration (EBUS-TBNA) is under-evaluated. Aims and Objectives: To determine the diagnostic yield and sample adequacy for molecular analysis of cell block over cytology in EBUS-TBNA. Method: Single-centre cross-sectional study was done in adults undergoing EBUS-TBNA (PENTAX EB-1970UK, ECHO HD 22G needle) over last one year. Sample was processed as cytology and additional cell block using tissue coagulum clot method1. Continuous and categorical variables are described as mean ± SD and proportions respectively. Result: Of the 62 EBUS-TBNA performed, either cytology or cellblock was diagnostic in 50 patients (yield 80%). Both cytology & cellblock was available in 47 patients (mean age 51.25±12.8 years, 36 males) whose data is analysed for this study. On an average three passes were made per lymph node. The overall daignostic yield was 92% (23/25 patients) in metastatic lymphadenopathy and in 53.3% cases cellblock had added benefit of definite histology subtyping using immunohistochemistry and judged to be adequate for molecular analysis in 80% cases. Among patients with granulomatous lymphadenitis, overall yield was 85% (17/20 patients) and cytology alone was sufficient for diagnosis in 15 (75%) patients whereas additional 2 (10%) cases were diagnosed by cell block. Conclusion: Cellblock preparation of EBUS-TBNA sample should be routine to increase the diagnostic yield and for further molecular testing. Reference: 1. Yung RCW, Otell S, Illei P, Clark DP. Cancer Cytopathol. 2012; 120(3):185–195.