Bing Neel Syndrome in a Previously Untreated Patient With Waldenström's Macroglobulinemia: Contribution of MYD88 L265P Mutation on Cerebrospinal Fluid

Bing Neel Syndrome (BNS) is defined as direct central nervous system involvement of Waldenstrom’s macroglobulinemia. BNS is usually a late event, although an incidence of 30% to 36% has been described in large series of previously untreated patients. A wide variety of clinical manifestations and radiologic findings for BNS have been reported in published data, depending on the site and type of infiltration. In addition to the radiologic findings, the diagnostic approach includes lymphoplasmacytic cell quantitation and flow cytometric analysis of the cerebrospinal fluid (CSF). Recently, the evaluation of MYD88 L265P mutation in the CSF has been proposed as a possible diagnostic biomarker for BNS. We describe the case of a 58-year-old patient with BNS. The detection of MYD88 L265P mutation in the CSF contributed to the diagnosis and to the sequential monitoring of minimal residual disease. In the future, the use of CSF sequential molecular monitoring could play an important role in treatment decisions.