Endobronchial ultrasound as a diagnostic tool in patients with mediastinal lymphadenopathy

The diagnostic yield and accuracy of new approaches to diagnose cancer should focus on comparison with established surgical techniques. Our objective was to evaluate the diagnostic performance of endobronchial ultrasound (EBUS) to detect cancer in patients with radiographically abnormal mediastinal lymph nodes.

The medical records of patients who underwent EBUS and had abnormal mediastinal lymph nodes (short-axis >1 cm and [or] positron emission topography-positive) over a 25 month period at the University of Pittsburgh were reviewed. Demographic and clinical data, cytology, and pathology results were entered in a database and analyzed.

A total of 172 patients [male to female = 1.8:1; median age, 67 years (range, 20 to 90]) were included. The diagnostic yield of EBUS cytology was 79.7% (137 of 172). Pathologic testing was available in 68% (117 of 172) and 82% (96 of 117) had a diagnostic EBUS. The diagnostic accuracy of EBUS was 91.7%. The sensitivity, specificity, positive (PPV) and negative (NPV) predictive values were 88.1% (95% confidence interval [CI], 77.3 to 94.3), 100% (95% CI, 85.9 to 100), 100% (95% CI, 92.4 to 100), and 80.6% (95% CI, 63.4 to 91.2), respectively. In 67 patients who had a suspected or biopsy-proven primary lung cancer, diagnostic yield was 86.6% and accuracy was 94.8%. In this subgroup the sensitivity, specificity, PPV, and NPV were 93% (95% CI, 76.5 to 98.9), 100% (95% CI, 69.9 to 100), 100% (95% CI, 85 to 100), and 83.3% (95% CI, 56.2 to 97.5).

Diagnostic performance data support the clinical usefulness of EBUS in the evaluation of patients with a radiographically abnormal mediastinum. It should be considered complementary to mediastinoscopy rather than substitutive.