Waldenström's macroglobulinemia associated with amyloidosis and membranous nephropathy.

A 61-year-old man with massive proteinuria and hyper gamma-globulinemia was admitted to hospital because of massive edema and pulmonary infection. He showed significantly high level of serum IgM (3244 mg/dl) with lambda-type M-protein and Bence Jones protein detected by immunoelectrophoresis. Renal biopsy specimen showed not only the diffuse amorphous amyloid deposition in mesangial area but global thickening of capillary wall with spike formation by silver staining which was similar to the spicular formation. Immunofluorescence disclosed find granular deposition of IgG and C3 along the capillary wall and the electromicroscopic findings clearly showed both massive amyloid fibril at mesangial area and diffuse epimembranous electron dense deposits. lambda-type Bence Jones protein in macroglobulinemia was suggested not only the cause of renal amyloidosis but also the antigenic origin of membranous nephropathy in this case.