Negative Predictive Value of Granulomas on EBUS-TBNA in Suspected Extrathoracic Malignancy

Abstract

Purpose: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a well-established diagnostic tool for lung cancer, sarcoidosis, and suspected metastatic extrathoracic malignancy. EBUS-TBNA carries a high diagnostic yield, but its negative predictive value (NPV) requires further clarification.

Methods: We reviewed EBUS-TBNA at our cancer center from 2008 to 2015. We identified negative diagnostic samples for adenopathy suspected to represent metastatic disease from extrathoracic malignancy.

Results: We reviewed 529 EBUS-TBNAs. Ninety patients underwent EBUS-TBNA sampling of the hilum and/or mediastinum (121 nodes, 14 masses) for suspected extrathoracic malignancy. Thirty-seven patients had negative samples (lymph node, granulomas or non-diagnostic specimens). The overall NPV was 98 %. Granulomas (11 patients, 25 nodes) seen on histology had a 100 % NPV, including those that were FDG-PET (fluorodeoxyglucose positron emission tomography) avid (n = 14 nodes).

Conclusion: Negative EBUS-TBNA in patients with extrathoracic malignancy and suspected secondary hilar or mediastinal metastases can infer a high NPV especially if granulomas are seen on histology. Larger prospective investigations are needed to confirm the high NPV of EBUS-TBNA with granulomas in extrathoracic malignancies.

Keywords: EBUS-TBNA; Extrathoracic malignancy; Granulomas.