Myeloma and plasmacytoma

Epidemiology
20,000 cases per year; 11,000 deaths in the US
Incidence is increasing

Risk factors
Age
Male sex
History of MGUS
More common in blacks

Diagnostic criteria for multiple myeloma
Patient needs one major and one minor or three minor criteria
Major criteria
Bone biopsy-proven plasmacytoma
Higher than 30% plasma cells on bone marrow biopsy
Monoclonal globulin spike

Minor criteria
Bone marrow with 10-30% plasma cells
Small M protein spike
Lytic bone lesions
Elevated IgM/IgA/IgG

The stage of multiple myeloma is affected by Hgb, serum calcium, Ig levels, renal function, B2-microglobulin concentrations

Myeloma vs. plasmacytoma

	Multiple myeloma	Plasmacytoma
Age	60's-70's	50's-60's
Number of bone lesions	Multiple	Single
Marrow	Increased plasma cells	Normal
RT dose	25Gy	40-45Gy

Bone vs. extramedullary plasmacytoma

	Bone	Extramedullary
Site	Spine	Head and neck
Rate of progression to MM	60-80%	10-40%
Dose	40-45Gy	45-50Gy
10-year OS	50%	60-80%