Disease	Distinctive features
MGUS	M protein < 3 g per dL (30 g per L), < 10% plasma cell in bone marrow, no urine M protein, no lytic lesions, anemia, hypercalcemia or renal disease
SMM	M protein > 3 g per dL (30 g per L), > 10% plasma cell in bone marrow, no lytic lesions, no anemia, hypercalcemia or renal disease
PCL	> 20% plasma cell in peripheral blood, small levels of M protein, few bone lesions, few hematologic disturbances; younger population
SP	Only one tumor with no other bone lesions, urine or serum abnormalities
WM	IgM M protein, hyperviscosity, hypercellular bone marrow with extensive infiltration by lymphoplasma cells
HCD	M protein with an incomplete heavy chain lacking a light chain