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 of 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.
References:
- 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]
- Avet-Loiseau H, Davies FE, Samur MK, Corre J, D’Agostino M, Kaiser MF, Raab MS, Weinhold N, Gutierrez NC, Paiva B, Neri P, Weisel K, Maura F, Walker BA, Bustoros M, Stewart AK, Usmani SZ, Hillengass J, Chng WJ, Keats JJ, Martinez-Lopez J, Sperling AS, Touzeau C, Zhan F, Raje NS, Cavo M, Bolli N, Ghobrial IM, Dhodapkar MV, Jagannath S, Spencer A, Parekh S, Bahlis NJ, Lonial S, Sonneveld P, Bergsagel L, Orlowski RZ, Morgan G, Mateos MV, Rajkumar SV, San Miguel JF, Anderson KC, Moreau P, Kumar S, Prósper F, Munshi NC. International Myeloma Society/International Myeloma Working Group Consensus Recommendations on the Definition of High-Risk Multiple Myeloma. J Clin Oncol. 2025 Aug 20;43(24):2739-2751. [Medline]
Created Sep 29, 2015.
Up-date Mar 18, 2026.
