ABSTRACT
Monoclonal gammopathy of undetermined significance (MGUS) is defined by a monoclonal immunoglobulin in serum of <3 g/dL, fewer than 10% plasma cells in the bone marrow and no evidence of lytic bone lesions, anemia, hypercalcemia, or renal insufficiency related to the plasma cell proliferative process. More than 50% of patients with a monoclonal gammopathy at Mayo Clinic have MGUS. IgG is the most common type of M protein.
