Factors influencing the diagnostic yield of endobronchial ultrasound-guided transbronchial needle aspiration

We describe the diagnostic performance of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in a heterogeneous population of patients with mediastinal lymphadenopathy secondary to suspected cancer (lung and nonlung) or recurrence after cancer therapy in a large academic cancer institute. A review was done of all patients referred for real-time EBUS- TBNA over an 18-month period at our institution. Cytological analysis of EBUS-TBNA aspirates was compared with a reference standard of definitive pathologic tissue diagnosis or a composite of ≥ 6 months' clinical follow-up with radiographic imaging. Adequate tissue was obtained in 225/236 procedures (95.3%) and a reference standard was available in 214. The overall diagnostic yield of EBUS-TBNA in those procedures with a reference standard was 87.4%. The sensitivity, specificity and diagnostic accuracy of EBUS-TBNA for malignancy was 86.1%, 100% and 92.9%, respectively. The sampling accuracy of EBUS-TBNA decreased with lymph node size < 5 mm and with paratracheal location. Other factors, such as airway distortion and calcification, are also associated with less accurate EBUS-TBNA results. In a diverse population of patients with suspected cancer or recurrence, EBUS-TBNA is minimally invasive and highly accurate. Factors such as lymph node size and location influence the result of EBUS-TBNA.