30 Abnormality of the Azygoesophageal Recess on

Computed Tomography

CLINICAL IMAGAGINGAN ATLAS OF DIFFERENTIAL DAIGNOSIS

EISENBERG

DR. Muhammad Bin Zulfiqar PGR-FCPS III SIMS/SHL

• Fig C 30-1 Normal appearance. CT scan shows the azygoesophageal recess (white arrow) formed by the esophagus anteriorly (black arrow) and the azygos vein posteriorly (arrowhead). The azygoesophageal line seen on plain radiographs represents the interface between this recess and the lung.52

• Fig C 30-2 Lymph node enlargement. (A) Enlargement of subcarinal lymph nodes (arrow) in a patient with malignant lymphoma produces reversal of the normal convexity at the level of the bronchus intermedius. The tumor cannot be delineated from mediastinal structures. (B) In a different patient with metastases from bronchogenic carcinoma of the right lower lobe, a scan obtained during the infusion of intravenous contrast material shows a distinct enlarged node (arrow) bulging into the recess at the level of the middle lobe bronchus.60

• Fig C 30-3 Dilatation of the descending aorta. (A) The aorta pushes lung away from the azygoesophageal recess. (B) At the level of the bronchus intermedius in a patient with a right-sided descending aorta, the azygoesophageal recess is markedly distorted by the descending aorta's bulging toward the right lung.60

• Fig C 30-4 Carcinoma of the esophagus. Feeding tube in lumen. (A) At a level corresponding to the ventricular cavities, there is thickening of the esophageal wall with reversal of the normal curvature of the azygoesophageal recess (arrow). (B) At the level of origin of the middle lobe bronchus, there is even more prominent bulging into the right lung because of prestenotic dilatation of the esophagus (arrow).59

• Fig C 30-5 Hiatal hernia. Large gas- and fluid-filled structure (arrow) that causes a rightward bulge of the distal azygoesophageal recess.63

• Fig C 30-6 Bronchogenic cyst. Subcarinal mass (arrow) producing an abnormal convexity of the azygoesophageal recess.52

• Fig C 30-7 Pleural mesothelioma. At the level of the right main bronchus, irregular pleural-based masses (arrow) that are most prominent anteriorly cause posterior displacement of the ascending aorta (A).60

• Fig C 30-8 Atelectasis. Collapse of the superior segment of the right lower lobe from bronchogenic carcinoma causes loss of demarcation between mediastinum and lung at the level of the middle lobe bronchus.60