28 Posterior Mediastinal Lesions on Computed Tomography

CLINICAL IMAGAGINGAN ATLAS OF DIFFERENTIAL DAIGNOSIS

EISENBERG

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

• Fig C 28-1 Bochdalek hernia. (A) Intra-abdominal fat and (B) the top of the left kidney (K) extend through a posterior defect (arrowheads) in the left hemidiaphragm.44

• Fig C 28-2 Esophageal duplication cyst. Enhanced scan at the level of the left atrium in an asymptomatic elderly man reveals a cystic periesophageal mass (arrow) with an attenuation value of 12 HU.59

• Fig C 28-3 Bronchogenic cyst. (A) Fluid-filled mass (arrow) in the posterior mediastinum.52 (B) Unenhanced scan of the upper abdomen in an asymptomatic young man shows a high-attenuation (55 HU) periesophageal mass (arrow).59

• Fig C 28-4 Mediastinal pancreatic pseudocyst. Unenhanced scan of the upper abdomen in a young man with acute pancreatitis demonstrates a periaortic fluid collection (long arrow) displacing the esophagus (short arrow) anteriorly.59

• Fig C 28-5 Ganglioneuroma. Huge posterior mediastinal mass (arrow) with poor contrast enhancement.

• Fig C 28-6 Hiatal hernia. (A) Enhanced scan of the upper abdomen reveals a lower esophageal or periesophageal mass (arrow). (B) A repeat scan obtained after oral administration of additional contrast material demonstrates a better-distended hiatal sac with gastric folds (arrow).59

• Fig C 28-7 Tuberculous spondylitis and paraspinal cold abscess. Unenhanced scan obtained above the aortic arch shows a paravertebral mass that is destroying the vertebral body (arrow) and displacing the trachea anteriorly.59

• Fig C 28-8 Parspinal abscess. Soft-tissue mass (arrow) extending bilaterally that effaced the paraspinal lines (arrow). Arowhead indicates descending thoracic aorta.52

• Fig C 28-9 Multiple myeloma. Unenhanced scan at the aortic arch level demonstrates a soft-tissue mass (white arrow) that is destroying the vertebral body and compromising the spinal canal. There are also associated osteolytic lesions of the posterior elements and adjacent ribs (black arrow).59

• Fig C 28-10 Hematoma. Large mediastinal soft-tissue mass (arrow) from multiple right transverse process fractures of the lower thoracic spine. Note the associated right hemothorax.63

• Fig C 28-11 Extramedullary hematopoiesis. Upper abdomen scan in a patient with homozygous sickle cell disease demonstrates bilateral, well-demarcated paravertebral soft-tissue masses (arrows) that are larger on the left. The diffuse increased attenuation of the liver reflects multiple blood transfusions.59

• Fig C 28-12 Mediastinal spread from bronchogenic carcinoma. There is obliteration of the fat plane around the descending aorta (DA) by the adjacent neoplasm (N) in addition to extension of tumor deep into the mediastinum (arrowheads) behind the left main-stem bronchus and in front of the descending aorta.46

• Fig C 28-13 Esophageal carcinoma. The circumferential mass of the bulky carcinoma (straight black arrows) fills the lumen of the esophagus (white arrow). Obliteration of the fat plane adjacent to the aorta (curved black arrow) indicates mediastinal invasion.

• Fig C 28-14 Achalasia. Dilated esophagus (arrow) filled with food and contrast material.63

• Fig C 28-15 Intrathoracic goiter. Enhanced scan above the aortic arch demonstrates a well-defined enhancing mass that displaces the esophagus (e), trachea (t), and major branches of the aortic arch and right brachiocephalic vein. There are areas of cystic degeneration (arrow) in the mass. Continuity with cervical thyroid tissue was seen on other images.59

• Fig C 28-16 Aneurysm of the descending aorta. Contrast-enhanced scan at a level just below the carina demonstrates a markedly dilated descending aorta (L) with a large mural thrombus (TH) surrounding the lumen of the descending aorta. Note also the markedly dilated ascending aorta (OA).

• Fig C 28-17 Dissecting aneurysm. (A) Level of the pulmonary artery. (B) More caudal level.

• Fig C 28-18 Azygos continuation of the inferior vena cava. (A) The dilated azygos vein (arrows) produces a posterior mediastinal mass. (B) Upper abdominal CT scan shows the dilated azygos vein (a) in a retrocrural position adjacent to the aorta

• Fig C 28-19 Esophageal and periesophageal varices. Scan of the lower chest obtained during a drip infusion of contrast material shows that the esophagus is compressed by extensive periesophageal varices and is not adequately visualized. The descending aorta (d) is also surrounded by the periesophageal varices.59