Differential diagnosis

This includes:

• benign monoclonal gammopathy:
  • there is no skeletal disease, no hypogammaglobinaemia, and no Bence Jones protein
  • observe if in doubt since there is no advantage to early treatment of asymptomatic multiple myeloma
• smouldering (asymptomatic) multiple myeloma
• symptomatic multiple myeloma
• plasmacytoma (1)
• reactive polyclonal hypergammaglobulinaemia - distinguished on basis of single or polyclonal spike
• other malignant lymphoproliferative diseases:
  • Waldenstrom's macroglobulinaemia
  • lymphomas
  • primary amyloidosis
  • osteosclerotic myeloma

Reference:

1. Sive, J., Cuthill, K., Hunter, H., Kazmi, M., Pratt, G., Smith, D. and (2021), Guidelines on the diagnosis, investigation and initial treatment of myeloma: a British Society for Haematology/UK Myeloma Forum Guideline. Br. J. Haematol., 193: 245-268.