To the editor:
Waldenström¿s macroglobulinemia (WM) is a lymphoproliferative disease characterized by the secretion of an IgM type monoclonal immunoglobulin. It occurs in patients with ymphoplasmocytic lymphoma and also in patients with other small B cell lymphomas. Typically, there is a lymphoplasmocytic infiltration of the bone marrow, lymph nodes, spleen, and occasionally of other tissues and organs like the kidney. Whether lymphoplasmocytic lymphoma and WM are the same condition is subject to controversy.1,2
Renal disease is basically due to IgM depositions in glomerular basal membrane and renal infiltration with lymphocytes or plasmacytoid cells.3 Despite this, renal failure is infrequent.
We present a 74 year-old male who was admitted to the Nephrology Department with a diagnosis of exacerbated chronic renal failure that required emergency hemodialysis. He went to the Hospital because of malaise, asthenia, diarrhea and nausea in the last five months. He had been evaluated at the Gastroenterology Department for 3 months and the creatinine value was 2 mg/dL. On physical exam he was pale, had cardiac arrhythmia, basal pulmonary hypoventilation, jugular ingurgitation, hepatomegaly, and edemas in both legs. In blood analysis anemia, thrombocytopenia, nitrogen retention (Creatinine 13 mg/dL) and metabolic acidosis were detected. ESR, IgM gammaglobulin and Kappa chains values were also elevated. A «rouleaux» phenomenon was seen. In urine there was no excretion of light chains. Bone marrow aspirate and biopsy disclosed infiltration of lymphocytes with plasmacytoid differentiation. The immunological study by means of flow cytometry was compatible with lymphoplasmocytic lymphoma. Renal biopsy showed: 22 histologically normal glomeruli and 3 sclerosed glomeruli. There was infiltration of the interstitium with small size atypical lymphocytes, plasmacytoid lymphocytes and plasma cells, which markedly widened the renal interstitium (fig. 1). By immunohistochemistry malignant cells were found to be positive for anti-CD20 and anti-CD3 anti-sera.
The etiology of WM is unknown but somatic mutations and chromosomal abnormalities of malignant B cell are present. Surface antigens expressed in atypical lymphocyte are mainly CD19, CD20, CD24 and light chain kappa.4 The clinical picture is similar to other malignant conditions with general syndrome, night sweating, fever, together with symptoms derived from organ involvement due to tumoral infiltration, IgM or amyloid protein deposition or hyperviscosity syndrome.1,3,5 The following renal manifestations have been described: glomerulonephritis, due to IgM or cryoglobulins depositions and nephrotic syndrome, commonly secondary to amyloidosis or to IgM thrombi within the glomerular capillaries.6-9
In the reported case, the patient presented with general and digestive symptoms, and renal failure without proteinuria, which prompted the decision to perform a renal biopsy. The pathological examination of the sample revealed interstitial renal infiltration with lymphoplasmocytic lymphoma with no IgM depositions.
We consider that this case is interesting because of the presence of renal failure, which is infrequent in this condition, and also because of the lack of proteinuria, probably due to lymphocytic infiltration of the interstitium that did not affect the glomeruli.
The patient initiated chemotherapy with chlorambucil and prednisone and he was maintained in on chronic hemodialysis until he died nine months after the diagnosis.
