Biclonal gammopathy--report of a case with primary gastrointestinal lymphoma.

A 61-year-old female patient had had abdominal pain for two months; primary gastrointestinal lymphoma of diffuse, large cell type histology was diagnosed. Bone marrow study was negative. Bimodal gamma globulin was found on serum protein electrophoresis. Immunoelectrophoresis and immunofixation confirmed the nature of biclonal gammopathy with a fast-migrating IgM-kappa band and a slow-migrating IgG-kappa band. Biclonal gammopathy is unusual, and only rarely have cases been reported. The immunologic and molecular implications of biclonal gammopathy are discussed.