RESUMO
Monoclonal gammopathies are associated with a wide range of renal diseases, including cast nephropathy, light chain amyloidosis, monoclonal immunoglobulin deposition diseases, and so on. We describe seven cases of monoclonal gammopathies involving kidney. The mean age was 61.6+/-3.6 years and male to female ratio was 1:1.3. Among 7 patients, diagnoses were cast nephropathy with light chain deposition disease, two light chain deposition diseases, three light chain amyloidosis and light chain deposition disease with light chain amyloidosis. Two cases were monoclonal gammopathy of undetermined significance and three cases were multiple myeloma in five cases underwent bone marrow biopsy. It showed that renal function was severly decreased in light chain deposition disease. It is clear that monoclonal gammopathies show various renal disease and clinical course in our cases. It is necessary to do renal biospy for adequate diagnosis and treatment even to old patients suspecting monoclonal gammopathy.