How to treat superior orbital fissure syndrome when the etiology is a neoplasm?

Treat the cause: Manage the neoplasm by whatever means is appropriate.

Treat the neoplasm: You need to know the nature of the neoplasm(a generic name saying it is likely cancer but you need to know what kind of cancer it might be). There is a specific treatment for each type of cancer. It can be either surgery or radiotherapy or sometimes it is chemotherapy. It all depends on the histologic diagnosis which requires doing a biopsy.