Nineteen‐year follow‐up of Waldenström's‐associated neuropathy and Bing–Neel syndrome

We describe the follow‐up of a patient with Waldenström's macroglobulinemia who developed mild predominantly sensory peripheral neuropathy, Bing–Neel syndrome, and, after 17 years, acute mononeuropathy multiplex associated with increasing paraprotein levels. Nerve biopsy demonstrated deposition of IgM in the endoneurium and perineurium. Magnetic resonance imaging showed extension of the cerebral white‐matter abnormality. We suggest that the pathogenetic mechanism of the mononeuropathy multiplex may include direct IgM deposition. Late peripheral nerve complications appeared to be related to the paraprotein level. © 2008 Wiley Periodicals, Inc. Muscle Nerve, 2009