This document contains 19 figures from an atlas showing different pathologies that can appear as posterior mediastinal lesions on computed tomography (CT) scans. The figures show examples of conditions like Bochdalek hernia, esophageal duplication cyst, bronchogenic cyst, mediastinal pancreatic pseudocyst, ganglioneuroma, hiatal hernia, tuberculous spondylitis, paraspinal abscess, multiple myeloma, hematoma, extramedullary hematopoiesis, mediastinal spread of bronchogenic carcinoma, esophageal carcinoma, achalasia, intrathoracic goiter, aneurysm of the descending aorta, dissecting aneurysm, azygos continuation of

1. 28Posterior Mediastinal Lesions
on Computed Tomography

2. CLINICAL IMAGAGING
AN ATLAS OF DIFFERENTIAL DAIGNOSIS
EISENBERG
DR. Muhammad Bin Zulfiqar
PGR-FCPS III SIMS/SHL

3. • 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

4. • 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

5. • 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

6. • 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

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

8. • 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

9. • 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

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

11. • 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

12. • 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

13. • 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

14. • 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

15. • 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.

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

17. • 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

18. • 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).

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

20. • 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

21. • 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