Answer: Retropharyngeal abscess. Enlarged retropharyngeal space secondary to soft tissue swelling anterior to the upper cervical bodies seen in a retropharyngeal abscess. 

From: Zaoutis LB, Chiang VW. Comprehensive Pediatric Hospital Medicine, 2e; 2017 Available at: http://accesspediatrics.mhmedical.com/ViewLarge.aspx?figid=170329862  Accessed: February 13, 2018