An asymptomatic 74-year-old man has a high erythrocyte sedimentation rate (ESR) noted on routine blood work done in a yearly physical examination. A follow-up protein electrophoresis reveals a monoclonal immunoglobulin G (IgG) spike. Which of the statements would suggest a plasma cell myeloma, rather than a monoclonal gammopathy of unknown significance?
(A) Bence Jones protein 2 g/day
(B) normal hemoglobin
© M component level of 2 g/dL
(D) bone marrow plasma cells of 5%
(E) normal serum calcium level
solution:
(A) IgG spikes >3.5 g/dL or IgA >2 g/dL strongly suggest myeloma rather than monoclonal gammopathies of undetermined significance (MGUS). MGUS is suggested when the spike is <3.5 g/dL, the marrow has fewer than 10% plasma cells, and the Bence Jones proteinuria is <1.0 g/day. Depressed hemoglobin levels, elevated calcium levels, progressive bone lesions, and impaired renal function suggest more advanced stages of multiple
myeloma.