Table 2.

Differential Diagnosis for MGUS, SMM, and Symptomatic MM

Feature	MGUS	SMM	Multiple Myeloma
BMPC, %	< 10	≥ 10	≥ 10
	and	and/or	and/or
Serum monoclonal protein, g/L	< 3	≥ 3	≥ 3
Clinical manifestation	Absent	Absent	Present*

NOTE. From the International Myeloma Working Group.

Abbreviations: MGUS, monoclonal gammopathy of undetermined significance; SMM, smoldering (asymptomatic) multiple myeloma; MM, multiple myeloma; BMPC, bone marrow clonal plasma cells.

^*Clinical features may include increased serum calcium concentrations, renal failure, anemia, skeletal involvement (lytic lesions), recurrent bacterial infections and/or extramedullary plasmacytomas.