Multiple Myeloma (MM)

Last updated 20.09.12

 

Definition

-  Proliferation of malignant plasma cells associated with monoclonal paraproteins

 

Features

-  1-2% all Ca

-  Avg age 68-70 yrs

-  Male 3:2 female

 

Cause

-  Idiopathic

-  ? Radiation

 

Dx

-  Combinations of

-  I + b, c or d

-  II + b, c or d

-  III + a, c or d

-  a + b + c

-  a + b + d

-  I = plasmacytoma on biopsy

-  II = bone marrow > 30% plasma cells

-  III = monoclonal globulin spike on electrophoresis

-  IgG > 3.5 g/dL

-  IgA > 2g/dL

-  Or Urine protein electrophoresis > 1g/24 hours

-  a = bone marrow 10-30% plasma cells

-  b = monoclonal spike present but < III

-  c = lytic bone lesion/s

-  d = residual normal:

-  IgM < 50 mg/dL

-  or IgA < 100 mg/dL

-  or IgG < 600 mg/dL

 

DDx

-  Light Chain Amyloidosis

 

Staging

-  I: mean survival > 60 months

-  Hb > 10 g/dL

-  Ca < 12 mg/dL

-  Xray normal or solitary plasmacytoma

-  Low protein M

-  IgG < 5 g/dL

-  IgA < 3 g/dL

-  Urine < 4 g/24 hours

-  II: mean survival 40 months

-  Fits neither I nor III

-  III: mean survival 23 months

-  Hb < 8.5 g/dL

-  Ca > 12 mg/dL

-  Xray w lytic bone lesions

-  High protein M

-  IgG > 7 g/dL

-  IgA > 5 g/dL

-  Urine > 12 g/24 hours

-  Subcatergories

-  A = Cr < 2g/dL

-  B = Cr > 2g/dL

-  2-12 months less survival

 

Associated S/S:

-  Bone pain (70% pts)

-  Pathalogical #

-  Neuropathy

-  Cord compression

-  Carpal tunnel syndrome

-  Hypercalcaemia

-  Amyloidosis

-  Infections

-  Esp. encapsulated

-  VZV

-  Meningitis

-  CRF

-  Stroke, AMI: hyperviscosity

-  Pancytopaenia: fatigue, bruising..

 

Ix

-  FBE: pancytopaenia

-  CRP: prognosis

-  Serum protein: elevated (total protein – albumin = globulin)

-  Serum viscosity

-  Electrophoresis

-  Plasma: IgA, IgG, IgM

-  Urine: Bence Jones protein

-  24 Hour urine: proteinuria, CCR, Cr

-  Protein:Creatine: proteinuria

-  MRI: cord compression

-  X-ray: lytic bone lesions, pathalogical #

-  Beta 2 microglobin: prognosis

-  Bone marrow aspirate: plasma cell %, film

 

Mx

-  Bone marrow transplant

-  Delayed Tx does not limit efficacy

-  Allogeneic

-  HLA match if possible (twin best)

-  GVHD

-  Increased adverse events (mortality)

-  Autologous

-  Preferred

-  Risk of re-implantation

-  Chemotherapy

-  Melphalan + Prednisolone

-  Oral 4-7 days

-  Every 4-6 weeks

-  Radiation

-  Very sensitive

-  Lytic lesions & areas of bone pain

-  Bisphosphonates

-  EPO: anaemia

-  Plasmaphoresis: esp if renal damage

-  Steroids: for cord compression

-  Surgery: cord compression, Carpal Tunnel Syndrome, lytic lesions (pins)

 

 

 

References