Multiple Myeloma

• Clinical
  • Average age is 60-70
  • Men much more common than women
  • Most have an elevated serum protein with 80-90% in the globulin fraction, especially IgG
  • Bence-Jones protein in 40-60% of patients (light chains)
• X-ray findings
  • Osteoporosis is most common skeletal abnormality in this disease
  • Lesions are usually multiple and found in vertebrae, ribs, skull, pelvis, and femur
  • Over 50% of solitary lesions are found in vertebrae
  • Mandible involved in 1/3 of patients with diffuse involvement
  • Widespread lucencies in bone
    • Discrete, “punched-out” lesions
    • Uniform in size
  • Distinctive to MM are the lucent, elliptical, subcortical shadows, especially in long bones=endosteal scalloping
    • Due to buttressing since MM is usually a slower process than mets
  • In spine, MM destroys body and spares pedicle
• DDX: mets and disuse osteoporosis
  • MM is more widespread
  • More discrete holes in MM
  • Large foci of coalescence more often due to mets
  • Severe disuse osteoporosis may simulate bone changes of MM
• Sclerosis is usually seen only with treatment or fracture
  • Bone scans may typically be negative and many hot areas on scan may be healing fractures
• Most believe that almost all patients with a solitary plasmacytoma will develop multiple myeloma
  • Solitary plasmacytoma produces “soap-bubbly” expansile, septated lesion, when characteristic

Multiple myeloma . The pelvis contains numerous lytic lesions without reactive sclerosis which
have an almost "soap-bubbly" appearance in the ischia. There are also lytic lesions in
both proximal femora.

Other examples of Multiple Myeloma (Click on each to enlarge)