IgM Monoclonal Gammopathy of Undetermined Significance
IgM MGUS is considered as a precursor to lymphplasmacytic lymphoma (LPL) and/or Waldenstrom and is separate from Non-IgM MGUS (IgG, IgA), which is a precursor to plasma cell myeloma.
Category Archives: Multiple Myeloma
MGUS – Non-IgM
Monoclonal Gammopathy of Uncertain Significance (MGUS)
- < 3 gm/dL serum M protein (and)
- <10% clonal bone marrow plasma cells (and)
- Asymptomatic patients, no end organ damage (CRAB: hypercalcemia, renal insufficiency, anemia, bone lesions)
- No evidence of other B-cell lymphoproliferative disorder
Smoldering (Asymptomatic) Myeloma
Smoldering (Asymptomatic) Myeloma
- >3 gm/dL serum M protein (or) urinary M protein ≥500 mg/24 hours
- (and/or) 10-60% bone marrow plasma cells (usually 10-20% plasma cells)
- Asymptomatic patients with no evidence of end-organ damage or biomarker evidence of malignancy (myeloma-defining events)
Plasma Cell Leukemia (PCL)
- >20% clonal plasma cells in the peripheral blood (PB)
- (or) >2,000/μL absolute count in PB
Plasma Cell Neoplasms
2016 WHO Classification
- Monoclonal Gammopathy (MGUS) – IgM
- Monoclonal Gammopathy (MGUS) – Non-IgM
- Plasma Cell Myeloma
- Plasma Cell Myeloma – Variants
- Smoldering Plasma Cell Myeloma (Asymptomatic)
- Non-Secretory Myeloma
- Plasma Cell Leukemia
- Plasmacytoma
- Solitary Plasmacytoma of Bone
- Extraosseous Plasmacytoma
- Monoclonal Immunoglobulin Deposition Disease
Plasma Cell Myeloma
Plasma Cell myeloma (PCM) is a disorder of monoclonal plasma cells, which is almost always associated with a monoclonal immunoglobulin protein in the serum and/or urine along with end organ damage (e.g. lytic bone lesions, renal failure, etc.).