Adenoid cystic carcinoma of the right pterygopalatine fossa with right V2 numbness treated with chemoradiation. There is decrease in size of the enhancing tumor within the right cavernous sinus extending from the right foramen rotundum and pterygopalatine fossa, now measuring up to 5 mm in width, previously 8 mm. The skull base and adjacent internal carotid artery flow voids are otherwise intact. There is moderate mucosal thickening in the right maxillary sinus, mild mucosal thickening in the left maxillary sinus, and secretions in the left nasal cavity. There is fluid signal within the bilateral mastoid air cells.
Interval decrease in size of perineural tumor involving the second division of the right trigeminal nerve and extending in the cavernous sinus.