Mixed cryoglobulinaemia not related to hepatitis C virus, mesangiocapillary glomerulonephritis and lymphoplasmocytic lymphoma.

Kidney involvement associated to lymphoma is a known phenomenon but frequently not characterized due to the low frequency with which biopsies are realized in these patients. Several histological patterns can co-exist and happen unnoticed without a biopsy. Parenchyma infiltration in kidney for lymphoma has been found in 34% (post-mortem) and 14% (pre-mortem) and have low incident of clinical manifestations. Other patterns of renal injury are associated to lymphoma and minimal changes disease is especially related with Hodgkin's lymphoma. Renal lesions associated to paraprotein in lymphoplasmacytic lymphoma are an exceptional association, in spite of in 20% of them, appear cryoglobulinemia. There are a few cases reported in the literature with different histological patterns: light-chain disease, amyloidosis, and immunotactoid glomerulopathy related with kidney injury in patients with lymphoma. A 39-year-old male presented an association among paraproteinemia, membrano-proliferative glomerulonephritis no hepatitis C virus related and lymphoplasmacytic lymphoma with renal infiltration. This case emphasized the variety of renal lesions that lymphomas could trigger and the value of the nephropathology in the diagnosis and outcome of the hematologic diseases with paraproteinemia.