Adenoid Cystic Carcinoma, sphenoid sinus

58-year-old female with chronic nasal obstruction and headaches. Centered in the left sphenoid sinus region, with invasion into the basisphenoid on the left and extension into the left petrous apex region, there is a T1-hypointense, T2/FLAIR-hyperintense, solid and cystic enhancing mass which does not restrict diffusion. The mass extends to the distal petrous canal where there is greater than 180 degrees encasement of the left internal carotid artery without narrowing of its flow void. The lesion invades and enlarges the left cavernous sinus with elevation of the overlying dural surface. The differential diagnosis includes nasopharyngeal carcinoma, carcinoma of the minor salivary glands, such as adenoid cystic, lymphoma and chondrosarcoma. The final diagnosis was high-grade adenoid cystic carcinoma of the left sphenoid sinus. Adenoid cystic carcinoma can be considered low grade which tends to be well-defined, versus high grade which is more infiltrative. It can involve the submandibular/sublingual salivary glands, lacrimal glands, nasopharynx and hard palate.