Presentation
Parotid collection on ultrasound, abscess?
Patient Data
Lobulated ring enhancing lesion with central hypodensity involving the deep portion of the left masseter muscle with minor overlying subcutaneous stranding. The left third molar tooth shows decay and alveolus cavitation/abscess that breaks through the external mandibular cortex in contiguity with the masseter lesion. No periosteal reaction identified. A few likely reactive left level II lymph nodes. Parotid and submandibular glands are symmetrical and have normal appearances. The remainder of the deep neck spaces is unremarkable. Images lung apices appear normal.
Radiograph confirming the tooth decay and periapical abscess.
Case Discussion
This case shows a submasseteric abscess that clinically and sonographically was thought to be from the parotid gland. Third molar infection is probably the most frequent cause of this kind of head and neck abscess.