Key Points

• Endoscopic ultrasound (EUS) permits evaluation of the esophageal wall beyond the mucosa.
• EUS plays an important role in staging esophageal cancer.
• EUS confirms diagnosis of benign esophageal tumours.
• EUS can assist the diagnosis and staging of other malignancies accessible through the upper GI tract.
• Endosonography-directed fine-needle aspiration (EUS-FNA) allows sampling and cytologic evaluation of the esophageal wall and surrounding tissues.

Endoscopic ultrasound (EUS) allows examination of the esophageal wall and surrounding structures beyond that seen with traditional white light endoscopy. The ultrasound transducers adjacent to the gastrointestinal mucosa operate at relatively high frequencies and create detailed images of local structures, providing important information for the diagnosis, staging and treatment of benign and malignant diseases of the esophagus and adjacent structures.