The definition of plasma cell myeloma (PCM) has rested on identifying clinical and laboratory features that predict when a sufficient burden of plasma cells has accumulated that the patient will benefit from treatment.
Diagnostic criteria for plasma cell myeloma
Symptomatic plasma cell myeloma
- M-protein in serum or urine*
- Bone marrow (BM) clonal plasma cells or plasmacytoma†
- Related organ or tissue impairment heavy chain disease‡ (CRAB)
Asymptomatic (smoldering) myeloma
- M-protein in serum at myeloma levels (> 30 g/L) and/or ? 10% clonal plasma cells in BM
- No related organ or tissue impairment end-organ damage or bone lesions [CRAB] or myeloma-related symptoms
CRAB indicates hypercalcemia, renal insufficiency, anemia, bone lesions.
*No level or serum or urine M-protein is included. M-protein in most cases is > 30g/L of IgG or > 25g/L of IgA or > 1g/24 h of urine light chain, but some patients with symptomatic myeloma have levels lower than these.
†Monoclonal plasma cell usually exceed 10% of nucleated cells in the marrow, but no minimal levels are designated because ~ 5% of patients with symptomatic myeloma have < 10% marrow plasma cells.
‡The most important criteria for symptomatic myeloma are manifestations of end-organ damage including anemia, hypercalcemia, lytic bone lesions, renal insufficiency, hyperviscosity, or recurrent infections.
- Campo E, Swerdlow SH, Harris NL, Pileri S, Stein H, Jaffe ES. The 2008 WHO classification of lymphoid neoplasms and beyond: evolving concepts and practical applications. Blood. 2011 May 12;117(19):5019-32. [Medline]
- International Myeloma Working Group. Criteria for the classification of monoclonal gammopathies, multiple myeloma and related disorders: a report of the International Myeloma Working Group. Br J Haematol. 2003 Jun;121(5):749-57. [Medline]
Created Sep 29, 2015.