title: The right inferior supraazygous recess: a cause of upper esophageal pseudomass on double-contrast esophagography.
abstract: OBJECTIVE
  Our purpose was to characterize the radiographic features of a pseudomass impression on the upper thoracic esophagus, to determine the frequency of such a pseudomass both on double-contrast esophagography and on CT, and to elucidate the anatomic basis for this finding.
  
  
  METHODS
  Our study group consisted of 135 patients whose double-contrast esophagograms were reviewed retrospectively for the presence or absence of an extrinsic indentation on the right posterolateral wall of the upper thoracic esophagus. In another patient group, 50 CT scans of the chest were also reviewed for the presence or absence of a prominent right inferior supraazygous recess and an associated indentation on the upper thoracic esophagus.
  
  
  RESULTS
  Thirteen (9.6%) of the 135 barium studies revealed a smooth, gently sloping indentation on the right posterolateral wall of the upper thoracic esophagus. The indentations ranged from 5 to 10 cm in length and extended inferiorly from the thoracic inlet to or just below the aortic arch. Twenty-four (48%) of the 50 CT scans revealed a prominent right inferior supraazygous recess projecting behind the esophagus. In five cases (10%), this recess also caused a smooth indentation on the upper thoracic esophagus.
  
  
  CONCLUSIONS
  A pseudomass impression was seen on double-contrast radiography as a smooth, gently sloping indentation on the right posterolateral wall of the upper thoracic esophagus in approximately 10% of patients. The indentation probably represents a normal anatomic variant (i.e., an unusually prominent right inferior supraazygous recess) that should not be mistaken for adenopathy or other masses in the mediastinum impinging on the esophagus.
authors.affiliation: Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia 19104, USA.
authors.forename: J W
authors.initials: JW
authors.lastname: Sam
authors.forename: M S
authors.initials: MS
authors.lastname: Levine
authors.forename: W T
authors.initials: WT
authors.lastname: Miller
mesh_terms: D003287:Contrast Media / Q000008:administration & dosage*; D003937:Diagnosis, Differential; D004935:Esophageal Diseases / Q000000981:diagnostic imaging; D004947:Esophagus / Q000000981:diagnostic imaging*; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media