Abstract
Waldenström's macroglobulinemia (WM), characterized with monoclonal immunoglobulins of type M and lymphoplasmacytic lymphoma, is a rare clonal Bcell disorder. WM usually present as an indolent lymphoma, and renal involvement is, in contrast to multiple myeloma, very rarely seen. We present a patient presenting with severe nephritis and nephrotic range proteinuria of more than 9 g/day as initial manifestations of WM. Furthermore, we discuss diagnostic and therapeutic approaches for this rare manifestation of the disease, in the light of recent research and treatment recommendations.