Waldenstrom Macroglobulinemia Manifesting as Acute Kidney Injury and Bing-Neel Syndrome With Excellent Response to Ibrutinib.

Waldenstrom macroglobulinemia (WM) is a lymphoplasmacytic lymphoma associated with a monoclonal immunoglobulin M protein. Extranodal involvement in WM is not very common. In this article, we present a rare case of WM with kidney and central nervous system involvement. Bing-Neel syndrome is a distinct complication of WM where lymphoplasmacytic cells involve the central nervous system (CNS). Our patient was initially treated with dialysis and steroids with improvement in his kidney function. He was then started on systemic treatment with rituximab, cyclophosphamide, and dexamethasone with stable kidney function but persistent CNS symptoms. Due to rarity of cases, there is no standard treatment for Bing-Neel syndrome. His treatment was switched to ibrutinib with dramatic improvement in his CNS symptoms as well as radiological findings on magnetic resonance imaging.