Ophthalmoplegia Associated With Extramedullary Multiple Myeloma: Case Series From a Tertiary Cancer Center

Multiple myeloma (MM) is a malignant disorder of plasma cells that results in tumor cells replacing the bone marrow. In extramedullary MM (EMM), however, tumor cells proliferate outside the bone marrow. EMM may produce ophthalmoplegia through direct invasion of the superior orbital fissure, cavernous sinus, and/or sphenoidal sinus. Several mechanisms have been proposed including cranial nerve palsies, direct infiltration of bone, extraocular muscle metastasis, myelomatous meningitis, and parenchymal or paraneoplastic effects.We retrospectively reviewed the medical records of 7 patients at MD Anderson Cancer Center who suffered from ophthalmoplegia secondary to extramedullary MM between 2019 and 2021. We collected information regarding the symptoms, signs, radiographic and laboratory findings, management, complications, and prognosis of these patients throughout their disease course.Skull base MRI revealed 4 patients with ophthalmoplegias secondary to superior orbital fissure invasion, 2 patients with ophthalmoplegias secondary to cavernous sinus invasion, and 1 patient with ophthalmoplegia secondary to sphenoid sinus invasion.This is a case series describing 7 patients with ophthalmoplegias secondary to EMM. Our article is unique because of the size of the included cohort, which is large when compared with most English language publications detailing such ophthalmoplegias.