EBUS-TBNA in Extrathoracic Malignancies: Diagnostic and Prognostic Implications

Purpose In patients with extrathoracic malignancies (EM) the role of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for the assessment of abnormal mediastinal lymph nodes (MLN) is controversial. The aim of this study was to assess the diagnostic yield and prognostic significance of EBUS-TBNA in these patients. Methods Retrospective analysis of patients with EM and abnormal MLN detected by Computed Tomography (CT) and/or Positron Emission Tomography (PET). Results A total of 161 patients with EM and abnormal MLN were included (93 males, 58%). The most common EM was melanoma (19%) and gastrointestinal cancer (17%). Assessed lymph nodes were mediastinal in 70% of cases and hilar in 30%. The most frequently sampled lymph nodes were subcarinal (45%) and lower right paratracheal (21%). Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of EBUS-TBNA for the diagnosis of malignancy were 88%, 100%, 100% and 87%, respectively. These values were similar regardless the type of EM except for head and neck tumors where the NPV was particularly low (67%). The diagnosis of neoplastic involvement by EBUS-TBNA implied a worse prognosis in terms of overall survival ( p < 0.02) and cancer-specific survival ( p < 0.001). Conclusions In patients with EM and abnormal MLN, EBUS-TBNA has a high diagnostic yield. However, the NPV decrease in patients with head and neck tumors. Neoplastic MLN detected by EBUS-TBNA has prognostic implications in these patients.