May Be Caused by

 Common

Aortic aneurysm

Aortic ectasia

Aortic laceration

Infectious spondylitis

Osteophytes

Paraspinal hematoma

Paraspinal hemorrhage

Posterior mediastinal mass

Spinal neoplasm

Tuberculous spondylitis

 Uncommon

Dilated azygos vein

Esophageal dilatation

Esophageal neoplasm

Esophageal varices

Extramedullary hematopoiesis

Ganglioneuroblastoma

Ganglioneuroma

Lymphadenopathy

Lymphoma

Mediastinal edema

Mediastinal hemorrhage

Mediastinal varices

Neuroblastoma

Neurofibroma

Neurogenic tumor

Schwannoma