OPTIC DISC SWELLING IN POEMS SYNDROME: IS IT RELATED TO ENDONEURIAL EDEMA?

Fazio R., Bianchi Marzoli S., Servida P., Galardi G., Ciasca P., Del Carro U., Previtali S., Munerati E., Quattrini A. Departments of Ophthalmology and Visual Sciences, Haematology and Neurology, San Raffaele Scientific Institute, Milano, Italy. POEMS syndrome is a multisystemic disorder characterized by polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy and skin changes. The pathogenesis of these multiple systemic manifestations is still un‐ known. Peripheral neuropathy is a nearly universal finding in POEMS syndrome. The neuropathy is usually a progressive distal sensorimotor polyneuropathy. Peripheral nerve pathology is variable and includes axonal degeneration and demyelination. Endoneurial edema, another prominent feature of this peripheral neuropathy, and microvascular abnormalities, that may also be present, could account for some systemic manifestations of the syndrome. We report a 52‐year‐old woman with POEMS syndrome, optic disc swelling and a progressive peripheral polyneuropathy. Sural nerve biopsy showed both axonal loss and demyelination, endothelial damage and marked endoneurial edema. Corticosteroids resulted in rapid improvement of both optic disc swelling and peripheral neuropathy. This case may represent a novel example of extracellular edema of the optic nerve. Defect of the blood‐nerve barrier can cause endoneurial edema that manifests as both optic and peripheral neuropathy.