CT neck post contrast demonstrates:
- cystic lesion with rim enhancement and internal septations in the left suprahyoid neck
- transpatial lesion involving the left parotid, submandibular and visceral spaces
- internally there are some hyperdense and enhancing material
- inflammatory fat stranding in the adjacent tissues
- enlarged lymph nodes in the left cervical chain
- no bony abnormality
- lung apices clear
The imaging appearance favours an infected lymphatic malformation. A reasonable differential diagnosis includes a first branchial cleft cyst.