Endobronchial Ultrasound-guided Transbronchial Needle Aspiration in a Geographical Region With Endemic Histoplasmosis Infection.

ABSTRACT

BACKGROUND AND OBJECTIVE: In a geographical area with high prevalence of calcific granulomatous inflammation, calcified lymph nodes may affect the diagnostic adequacy of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). The objective of this study was to describe the diagnostic performance of EBUS-TBNA in a region endemic of histoplasmosis related granulomatous inflammation. METHODOLOGY: A retrospective review was done for all patients referred for EBUS-TBNA over a 7-month period at 2 institutions. Computed tomographic (CT) chest studies were reviewed in a blinded manner by 2 radiologists. In parallel, CT images from 100 unselected sequential control patients were reviewed. Cytologic analysis of EBUS-TBNA aspirates was compared with a reference standard of definitive pathologic tissue diagnosis or a composite of ≥6-month clinical follow-up. RESULTS: The prevalence of calcified lymph nodes in the 100 control patients was 56%. All 61 patients undergoing EBUS-TBNA were included. In total, 97 lymph nodes (mean size=13.8 mm) and 7 masses were biopsied. Definitive lymph node sampling was achieved in 51 of 61 patients (83%). The sensitivity, specificity, and positive and negative predictive values of EBUS-TBNA for malignancy (primary lung cancer staging, restaging, and reevaluation after cancer therapy, small cell lung cancer, lymphoma, and metastatic cancer) were 81%, 100%, 100%, and 84% respectively. On pre-EBUS CT chest scan, 60.6% had nodal calcification. The prevalence of cancer was not different in those with and without nodal calcification (49%). There was no difference in frequency of definitive lymph node sampling in those patients with or without nodal calcification. CONCLUSION: In a geographical area with endemic histoplasmosis-related nodal calcification, there was no evidence of nodal calcification affecting the frequency of EBUS-TBNA definitive lymph node sampling.