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:
- Bone marrow failure, as manifested by anaemia, leucopenia or thrombocytopenia.
- Renal insufficiency and/or hypercalcaemia.
- Lytic bone lesions or osteoporosis.
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:
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.
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.
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.
|See Hyperviscosity syndrome|
Usually normochromic, normocytic to macrocytic (round macrocytes).