Esophageal carcinomas: invasion of adjacent structures in computed tomography

Esophageal cancer may spread by direct extension to the tracheobronchial tree, aorta, pericardium, lungs, and diaphragm. The aim of the study is to present the CT images of esophageal carcinoma with invasion of surrounding structures. CT criteria of tracheobronchial invasion include the presence of an esophageal mass that displaces the trachea or bronchus from the spine or discrete indentation on the posterior wall of the trachea or bronchus on CT images. Bronchial stenosis or occlusion may be clearly seen in virtual bronchoscopy. An area of contact between the aorta and esophageal tumor greater than 90o is diagnostic for aortic invasion. Another criterion for predicting aortic invasion is obliteration of the triangular fat space between the esophagus, the aorta, and the spine. CT detection of pericardial invasion is based on the obliteration of fat planes and the presence of a mass effect or the presence of a mass effect with a concave deformity in this region. A fat plane separating the esophageal mass from the surrounding structures at all CT sections excludes an invasion. (author)