Benign monoclonal gammopathy presenting with severe renal failure.

A patient with monoclonal gammopathy and renal failure due to kappa light chain deposition in the glomerular basement membrane is reported. After 8 months, he developed a progressive and severe renal failure requiring haemodialysis. 30 months later, the monoclonal gammopathy was unchanged. Clinical features, as well as kinetic and immunological studies, were consistent with a diagnosis of benign monoclonal gammopathy (BMG). This case suggests that the renal failure complicating a monoclonal gammopathy is not related to its malignancy.