Background: The differential diagnosis for a paratracheal air collection includes Zenker diverticulum, tracheal diverticulum, apical herniation of the lung, and pneumomediastinum. In the setting of trauma, pneumomediastinum is traditionally regarded as an alarm sign that warrants investigation for tracheal or esophageal rupture,both highly morbid conditions.
Case report: A patient presented to the emergency department with neck pain several hours after being involved in a low-speed,side-impact automobile collision. She was discharged with analgesics after cervical spine radiographs showed no fracture and physical examination found no neurological deficits. She returned 18 days later with retrosternal pain and worsening neck pain, and cervical computed tomographic scan demonstrated an abnormal paratracheal air collection. Follow-up chest computed tomographic scan identified a right-sided tracheal diverticulum without evidence of pneumomediastinum.