Mediastinal Bronchogenic Cysts: Demonstration of Fluid-Fluid Level in Bronchoscopic US Imaging.

We report the findings for 2 patients with a fluid-fluid level seen on endobronchial ultrasound (EBUS) images of bronchogenic cysts. The EBUS images demonstrated a well-circumscribed cyst with a fluid-fluid level showing an anechoic upper part and a relatively hyperechoic lower part. A fluid-fluid level on EBUS imaging of a bronchogenic cyst, which can help confirm the cystic nature of the lesion, has not been previously reported. EBUS-based confirmation of these cysts using fluid-fluid levels may help avoid unnecessary aspiration of the lesions.