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Durie and Salmon PLUS Staging System

Classification

Bone Marrow

Laboratory Parameters

Imaging Parameters¹

Monoclonal gammopathy of undetermined significance (MGUS): Not included in staging

< 10% plasma cells

 

No intra- or extramedullary disease

Smoldering multiple myeloma (SMM): Stage IA²

≥ 10% plasma cells

All of the following: Hemoglobin > 10 g/dL; sCa++ ≤12 mg/dL; low M-component production; IgG < 5.0 g/dL; IgA < 3.0 g/dL; urine M-protein < 4g/24h

Limited disease (definition evolving)

Multiple myeloma (MM): Stages IB-III

≥ 10% plasma cells &/or plasmacytoma + end organ damage³

Variable by stage

Variable by stage

Stage IB²

 

Same as stage IA above

< 5 focal lesions4; mild diffuse disease5 on T1 MR

Stage IIA/B²

 

Neither stage I nor stage III

5-20 focal lesions4; moderate diffuse disease5 on T1 MR

Stage IIIA/B²

 

1 or more of the following: Hemoglobin < 8.5 g/dL; sCa++ > 12 mg/dL; IgG > 7.0 g/dL; IgA > 5.0 g/dL; urine M-protein > 12g/24h

> 20 focal lesions4; severe diffuse disease5 on T1 MR

¹The imaging appearance of bone marrow is variable. Patients with stage III myeloma by clinical criteria can have a normal MR appearance of bone marrow, which is associated with a more favorable prognosis. 
²A: Serum creatinine < 2.0 mg/dL & no extramedullary disease; B: Serum creatinine > 2.0 mg/dL &/or extramedullary disease. 
³"End organ damage" includes calcium elevation, renal insufficiency, anemia, or bone abnormalities. 
4 Focal lesions ≥ 5 mm. 
5 Degree of diffuse disease is evaluated on T1 images. Mild = micronodular or "salt and pepper" pattern of infiltration; moderate = diffuse lower T1 signal than normal marrow but with contrast between vertebral bone marrow and disc; severe = low T1 signal throughout the vertebral bone marrow with signal less than that of the adjacent disc.

International Staging System

Stage

Criteria

I

Serum β2-microglobulin < 3.5 mg/L

Serum albumin ≥ 3.5 g/dL

II

Not stage I or III

III

Serum β2-microglobulin ≥ 5.5 mg/L

The International Staging System is useful in imaging facilities without advanced imaging with MR or PET and as a measure of survival. Median survival for stage I: 62 months; stage II: 44 months; stage III: 29 months.

Χαρακτηριστικά Επέκτασης

  • Primarily intramedullary spread
  • Extramedullary spread, especially in advanced disease

Κατηγοριοποίηση (Ιστολογικοί Τύποι)

Based on increasing malignant potential

  • Monoclonal gammopathy (MG) of undetermined significance (MGUS)
    • Progression risk → multiple myeloma (MM) = 1% per year
    • < 3 g/dL serum M-protein & < 10% BM PCs
    • When progression occurs → usually to MM or Waldenström macroglobulinemia
    • Potentially can progress to
      • Primary amyloidosis
      • Chronic lymphocytic leukemia
      • Lymphoma
    • MG of borderline significance (MGBS)
      • Subclassification (not universally used)
      • Higher risk of progression to MM than MGUS
      • Difference = ↑ PC number in BM (10-30% for MGBS vs. < 10% for MGUS)
  • Smoldering multiple myeloma (SMM)
    • ≥ 3g/dL serum M-protein & ≥10% BM PCs
    • No end organ damage (EOD) (asymptomatic)
    • Higher risk of progression to MM
  • Multiple myeloma
    • Symptomatic: End organ damage present
    • EOD includes any of the following (CRAB)
      • Calcium elevation
      • Renal insufficiency
      • Anemia
      • Bone abnormalities (lytic or osteopenic)
    • Nonsecretory
      • No elevated M-protein in urine or blood
      • Disease best followed by PET/CT
    • IgD MM
    • POEMS syndrome
      • Polyneuropathy, organomegaly, endocrinopathy, M-protein, skin changes
      • Sclerotic bone lesions
      • PC leukemia is characterized by > 20% circulating PCs at any time