Orbital involvement in Bing-Neel syndrome.

Bing-Neel syndrome (BNS) is defined as intracranial involvement of Waldenström macroglobulinemia (WM). Few cases of orbital involvement have been reported. A 51-year-old man with a history of WM developed bilateral orbitopathy and optic neuropathy. Orbital biopsy, cerebrospinal fluid studies, and neuroimaging confirmed the diagnosis of BNS involving the orbital soft tissues, optic nerves, meninges, and cauda equina. The neuro-ophthalmic manifestations resolved after parenteral and intrathecal chemotherapy in addition to autologous stem cell transplantation. The rare neuro-ophthalmic manifestations of BNS may require a multifaceted approach to therapy.