[Place of ultrasound endoscopy in dysphagia].

Echo-endoscopy is a technique which has been shown to be effective in the staging of cancers of the oesophagus and cardia. It is indicated to guide the therapeutic choice according to the stage of regional extension, which is known to be the main prognostic factor of this disease. Echoendoscopy is a very elegant technique to visualise subepithelial vaulting, which can correspond either to a submucosal tumour, or to extrinsic compression by an adjacent organ or a mediastinal tumour infiltration. Echo-endoscopy can be useful to differentiate idiopathic megaoesophagus from secondary megaoesophagus by visualising a peri-oesophageal infiltration.