Cavernous sinus syndrome associated with metastatic colorectal cancer and perineural spread along the trigeminal nerve

Cavernous sinus metastasis from colorectal cancer is exceedingly rare. We report the second case of this entity with histopathologic confirmation, and the first case with concurrent perineural spread involving the trigeminal nerve. Cavernous sinus metastasis may represent a poor prognostic factor in colorectal cancer.