…..and the kidney biopsy solved the puzzle

Waldenstrom macroglobulinemia is an uncommon B-cell lymphoproliferative disorder characterized by bone marrow infiltration and immunoglobulin M gammopathy. Common symptoms are anemia, hepatomegaly, splenomegaly, and lymphoadenomegaly, along with elevated B2 microglobulin levels. Kidney involvement is rare. Mild proteinuria and microscopic hematuria are common but unspecific renal manifestations of the disease. Kidney biopsy findings include AL amyloidosis, direct infiltration by lymphoid cells, and, as in our patient, cryoglobulinemic glomerulonephritis with intracapillary aggregates of IgM. Heart involvement is quite rare in Waldenstrom macroglobulinemia and is usually due to amyloid deposition, however, we cannot exclude that our patient’s heart valve disease could be related to this diagnosis.