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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