THE RIGHT INFERIOR SUPRAAZYGOUS RECESS - A CAUSE OF UPPER ESOPHAGEAL PSEUDOMASS ON DOUBLE-CONTRAST ESOPHAGOGRAPHY

OBJECTIVE. Our purpose was to characterize the radiographic features o f a pseudomass impression on the upper thoracic esophagus, to determin e the frequency of such a pseudomass both on double-contrast esophagog raphy and on CT, and to elucidate the anatomic basis for this finding. MATERIALS AND METHODS. Our study group consisted of 135 patients whos e double-contrast esophagograms were reviewed retrospectively for the presence or absence of an extrinsic indentation on the right posterola teral wall of the upper thoracic esophagus. In another patient group, 50 CT scans of the chest were also reviewed for the presence or absenc e 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 indentatio n on the right posterolateral wall of the upper thoracic esophagus. Th e indentations ranged from 5 to 10 cm in length and extended inferiorl y from the thoracic inlet to or just below the aortic arch. Twenty-fou r (48%) of the 50 CT scans revealed a prominent right inferior supraaz ygous recess projecting behind the esophagus. In five cases (10%), thi s recess also caused a smooth indentation on the upper thoracic esopha gus. CONCLUSION. A pseudomass impression was seen on double-contrast r adiography as a smooth, gently sloping indentation on the right poster olateral wall of the upper thoracic esophagus in approximately 10% of patients. The indentation probably represents a normal anatomic varian t (i.e., an unusually prominent right inferior supraazygous recess) th at should not be mistaken for adenopathy or other masses in the medias tinum impinging on the esophagus.