Multiple myeloma

Last updated: Friday, 21, January, 2011

Myeloma is a malignancy of the plasma cell lineage characterised by:

1) A bone marrow infiltrate of plasma cells which is usually >10% of nucleated cells on bone marrow biopsy or the presence of a proven plasmacytoma.

2) A paraprotein in the urine and/or serum (~1% of myelomas are non-secretory). 

3) Myeloma related organ dysfunction:

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

A) MGUS (Monoclonal gammopathy of undetermined significance);

1. Monoclonal plasma cells <10%
2. Serum monoclonal protien <35g/1 (IgG), 20g/1 (IgA) and/or urine m-component <1g/24hr.
3. No evidence of myeloma-related organ dysfunction, lytic lesions, amyloidosis nor light chain deposition of the disease.

B) Smouldering Multiple Myeloma

1. Monoclonal protein present serum or urine.
2. Monoclonal plasma cells in bone marrow or tissue.

Not meeting the criteria for MGUS nor for myeloma.

ComplicationsAppropriate Tests

FBC, blood film; ESR; protein (total), albumin; protein electrophoresis, paraprotein typing (immunofixation), immunoglobulins G, A, M to identify and quantitate paraprotein and detect immune paresis.

Table 2 Reference intervals for immunoglobulins G, A, M (g/L)

Urine - protein, Bence Jones protein (light chain determination by immuno-electrophresis).

Bone marrow aspiration and trephine biopsy.

Creatinine, urea, calcium, phosphate, electrolytes. Beta-2-microglobulin may be useful to establish tumour load (prognostic significance) and for monitoring.

Chromosome studies may provide prognostic information.

Viscosity - plasma, occasionally useful.

Hypercalcaemia

Pathological fracture 

See Bone fracture (pathological)

Nephrotic syndrome

Renal failure

Immunodeficiency

Infection (increased susceptibility)

Hyperviscosity

See Hyperviscosity syndrome

Bleeding

  • Paraprotein effects 

See Paraproteinaemia

Anaemia, especially 

Usually normochromic, normocytic to macrocytic (round macrocytes).

  • Disease progression
  • Cytotoxic drugs and/or irradiation

Amyloidosis