A device used to look at tissues in the esophagus. It is a tiny capsule with a laser scanner inside and a very thin cord attached to it. The patient swallows the capsule and the thin cord helps keep the capsule in a specific area in the esophagus. The cord is also used to remove the capsule. Pictures are taken by the laser scanner and sent to a computer for viewing. A tethered capsule endoscope is used to find early cancers of the esophagus and other parts of the body. Also called TCE.