Plasma cell myeloma

Keywords: Myeloma, Multiple myeloma

A bone marrow-based, multifocal plasma cell neoplasm associated with an M-protein (i.e. abnormal immunoglobulin fragment or immunoglobulin light chain) in serum and/or urine.

Symptomatic plasma cell myeloma diagnosis requires:

1) Bone marrow infiltrate of clonal plasma cells (usually >10% of nucleated cells on bone marrow biopsy although no minimum percentage is designated in WHO diagnostic criteria) or the presence of a proven plasmacytoma.
 
2) A paraprotein in the urine and/or serum (~3% of myelomas are non-secretory).
 
3) Related organ or tissue impairment:

  • Anaemia
  • Renal insufficiency
  • Hypercalcaemia.

Lytic bone lesions or osteoporosis.

A diagnosis of plasma cell myeloma requires all three of the above features. For patients who do not meet the above criteria, consider a diagnosis of:

Asymptomatic (or smoldering) plasma cell myeloma 
1. Monoclonal protein present serum or urine at myeloma levels (>30g/L)
2. 10% or more clonal plasma cells in bone marrow
3. No related organ or tissue impairment or myeloma-related symptoms.
 
Monoclonal gammopathy of undetermined significance (MGUS)
1.     Monoclonal protein <30g/L,
2.     Bone marrow clonal plasma cells <10%
3.     No organ damage
4.     No evidence of B-cell lymphoma or other disease known to produce M-protein.

Key information

Appropriate Tests

 

Full blood count, Blood film; Erythrocyte sedimentation rate; Protein, Albumin; Protein electrophoresis, Paraprotein typing (immunofixation), Immunoglobulins G, A, M to identify and quantitate paraprotein and detect immune paresis.

Table 2.

Protein urine, Bence Jones protein urine (light chain determination by immuno-electrophoresis).

Bone marrow aspiration and trephine biopsy.

Assessment of disease burden (with CD138 immunohistochemical staining of trephine) and risk stratification.

  • Flow cytometry – clonal plasma cells are CD138, CD38 and CD79a (similar to normal plasma cells), but are negative for CD19 (unlike normal plasma cells). Clonality is based upon demonstration of cytoplasmic light chain restriction. 70% of cases are CD56+, which is typically negative in normal plasma cells and in plasma cell leukaemia.
  • Cytogenetics and FISH for risk stratification
    • Conventional cytogenetics for del13, Monosomy 13, hypodiploidy.
    • FISH for  t(11;14), t(6;14), t14;16), t14;20), del17p13, trisomies of odd numbered chromosomes

Creatinine, Urea, Calcium, Phosphate, Electrolytes. Beta-2-microglobulin may be useful to establish tumour load (prognostic significance) and for monitoring.

Imaging for bone disease.

Hypercalcaemia

 

Pathological fracture

See Bone fracture (pathological)

Nephrotic syndrome

 

Renal failure

 

Immunodeficiency

 

Infection (increased susceptibility)

 

Hyperviscosity

See Hyperviscosity syndrome

Bleeding

 

  • Thrombocytopenia

 

  • Paraprotein effects

See Paraproteinaemia

Anaemia, especially

Usually normochromic, normocytic to macrocytic (round macrocytes).

  • Disease progression

 

  • Cytotoxic drugs and/or irradiation

 

Amyloidosis