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