Monocular visual loss in a disseminated colorectal malignancy-A case report of a rare skull base metastasis.

Neoplasms of the orbit may be primary, secondary (infiltration from the adjacent structures), or metastatic (from distant structures). It can be divided into 3 histologic categories: benign, benign but locally aggressive, and malignant. Primary and secondary orbital tumors, including intra-orbital and optic nerve tumors are uncommon observations in daily medical practice. Orbital tumors represent approximately 0.1% of all tumors and approximately 18% of all orbital diseases. We report a case of a 42 year old male patient with colorectal malignancy with basal skull metastasis involving the orbital apex and involving the optic nerve causing visual loss.