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This neoplasm is not reportable.
Name
ICD-O-3 Morphology
9765/1: Monoclonal gammopathy
Effective
2001 and later
Reportability
This neoplasm is not reportable
Primary Site(s)
See Abstractor Notes
Primary site bone marrow (C421)
This hematopoietic disease is not reportable for the U.S.
Canada, refer to your specific province for reportability requirements.
This hematopoietic disease is not reportable for the U.S.
Canada, refer to your specific province for reportability requirements.
Abstractor Notes
Monoclonal gammopathy of undetermined significance (NOS) (MGUS) is part of the Plasma cell neoplasms and other diseases with paraproteins lineage table in the WHO 5th edition of Hematolymphoid Tumors. (See Appendix B in the Hematopoietic Manual, Table B17)
For non-IgM, neoplastic cells reside in the bone marrow.
Non-IgM MGUS is generally not associated with clinical symptoms, especially myeloma-associated clinical manifestations. It is usually diagnosed incidentally on laboratory tests done during the workup of a variety of unrelated medical conditions.
For monoclonal gammopathy of renal significance, the kidney is always invovled. May also involve the bone marrow or lymph nodes.
For non-IgM, neoplastic cells reside in the bone marrow.
Non-IgM MGUS is generally not associated with clinical symptoms, especially myeloma-associated clinical manifestations. It is usually diagnosed incidentally on laboratory tests done during the workup of a variety of unrelated medical conditions.
For monoclonal gammopathy of renal significance, the kidney is always invovled. May also involve the bone marrow or lymph nodes.
Alternate Names
Monoclonal gammopathy of renal significance (MGRS)
Monoclonal gammopathy, NOS (unassociated, unattributed, non-myelomatous)
Non-IgM monoclonal gammopathy of undetermined significance (Non-IgM MGUS)
Definition
Non-IgM monoclonal gammopathy of undetermined significance (MGUS) is defined by the presence of a non-IgM (mainly IgG or IgA; rarely IgE, IgD, and light chain only) serum monoclonal (M) protein of < 3 g/dL, clonal bone marrow plasma cells < 10%, and absence of end-organ damage, such as hypercalcemia, renal insufficiency, anemia, and bone lesions (CRAB), that can be attributed to the plasma cell proliferative disorder. Light chain MGUS is a subtype characterized by an abnormal serum free light chain ratio (< 0.26 or > 1.65), increased level of the involved light chain, no immunoglobulin heavy chain expression on immunofixation, and an absence of end-organ damage that can be attributed to the plasma cell proliferative disorder. (WHO 5th edition)
Monoclonal gammopathy of renal significance (MGRS) is a plasma cell or B-cell neoplasm that does not meet the accepted criteria for malignancy or initiation of treatment but secretes a monoclonal immunoglobulin (Ig) or Ig fragment resulting in kidney injury. It is important to note that renal impairment secondary to light chain cast nephropathy in plasma cell neoplasm is a multiple myeloma / plasma cell myeloma–defining event. (WHO 5th edition)
Monoclonal gammopathy of renal significance (MGRS) is a plasma cell or B-cell neoplasm that does not meet the accepted criteria for malignancy or initiation of treatment but secretes a monoclonal immunoglobulin (Ig) or Ig fragment resulting in kidney injury. It is important to note that renal impairment secondary to light chain cast nephropathy in plasma cell neoplasm is a multiple myeloma / plasma cell myeloma–defining event. (WHO 5th edition)
Definitive Diagnostic Methods
This data item does not apply
Genetics Data
This data item does not apply
Immunophenotyping
This data item does not apply
Transformations to
This data item does not apply
Corresponding ICD-10 Codes (Cause of Death codes only)
D47.2 Monoclonal gammopathy
Corresponding ICD-10-CM Codes (U.S. only)
D47.2 Monoclonal gammopathy (effective October 01, 2015)
Sources
WHO Classification of Tumours Editorial Board. Haematolymphoid tumours. Lyon (France): International Agency for Research on Cancer; 2024. (WHO classification of tumours series, 5th ed.; vol. 11). https://publications.iarc.who.int/637.
Section: Plasma cell neoplasms and other diseases with paraproteins
Pages: Part B: 603-604
Section: Plasma cell neoplasms and other diseases with paraproteins
Pages: Part B: 603-604
International Classification of Diseases for Oncology, 3rd edition (including revisions). Geneva: World Health Organization, 2001, 2011, 2020.
Section: ICD-O-3.2 (2020) Morphological Codes
Pages: Non-IgM monoclonal gammopathy of undetermined significance
Section: ICD-O-3.2 (2020) Morphological Codes
Pages: Non-IgM monoclonal gammopathy of undetermined significance
PDQ® Adult Treatment Editorial Board. PDQ Plasma Cell Neoplasms (Including Multiple Myeloma) Treatment. Bethesda, MD: National Cancer Institute. Updated <03/28/2025>. Available at: https://www.cancer.gov/types/myeloma/hp/myeloma-treatment-pdq. Accessed <03/30/2025>. [PMID: 26389362]
Section: Plasma Cell Neoplasms (Including Multiple Myeloma) Treatment (PDQ®)–Health Professional Version
Pages: https://www.cancer.gov/types/myeloma/hp/myeloma-treatment-pdq
Section: Plasma Cell Neoplasms (Including Multiple Myeloma) Treatment (PDQ®)–Health Professional Version
Pages: https://www.cancer.gov/types/myeloma/hp/myeloma-treatment-pdq
