Case Report: Cavernous Sinus Syndrome as the Initial Presentation of Multiple Myeloma

Multiple myeloma (MM) is the second most common hematologic malignancy and most common primary bone malignancy. Ocular manifestations of MM are extremely rare and may be the first presentation leading to diagnosis. Ophthalmologists routinely encounter cavernous sinus syndrome, and there is a wide range of possible etiologies. Here, we present a case of a patient presenting with diplopia, ptosis, and ophthalmoplegia found to have a cavernous sinus plasmacytoma with systemic workup consistent with MM. MM is a rare cause of cavernous sinus syndrome and should be considered in the setting of a skull base mass.