Presentation
Painless swelling the right submandibular region.
Patient Data
A well-circumscribed lobulated soft tissue mass within the right prestyloid parapharyngeal space in contact with the deep lobe of the parotid gland, displacing the adjacent pharyngeal tonsil anteromedially. It shows a low signal intensity on T1, high signal intensity on T2, and progressive and heterogeneous enhancement on postcontrast sequences. No restricted diffusion is seen on DWI/ADC. The internal carotid artery and the internal jugular vein are displaced posteriorly.
An incidental small pituitary lesion is noted, but not fully characterized.
Case Discussion
The location and the MRI features are suggestive of a parapharyngeal pleomorphic adenoma arising probably from the deep parotid lobe or the minor salivary glands.
The main differential diagnosis in this location include