Nonsecretory plasma cell myeloma--becoming even more rare with serum free light-chain assay: a brief review.
BACKGROUND
Nonsecretory plasma cell myeloma is characterized by an absence of detectable monoclonal protein in both the serum and urine. It is generally reported to comprise approximately 1% to 5% of all cases of plasma cell myeloma and, because of its rarity, requires a high index of suspicion and bone marrow biopsy to establish the diagnosis.


OBJECTIVE
Review the diagnostic strategy when nonsecretory plasma cell myeloma is a clinical consideration in light of a relatively new serum free light chain assay.


METHODS
Case study and review of the literature.


CONCLUSIONS
Initial data using a recently developed nephelometric serum free light chain assay suggests that only about one fourth of nonsecretory plasma cell myeloma cases may be truly nonsecretory. The definition of nonsecretory plasma cell myeloma should be modified to exclude cases with evidence of clonality using the serum free light chain assay.
Shaw
Gene R
GR
Marshfield Laboratories, Marshfield, Wis 54449, USA. shaw.gene@marshfieldclinic.org
D000361:Agammaglobulinemia / Q000097:blood / Q000175:diagnosis; D001854:Bone Marrow Cells / Q000473:pathology; D006801:Humans; D007118:Immunoassay / Q000379:methods; D007147:Immunoglobulin Light Chains / Q000097:blood*; D009194:Myeloma Proteins / Q000032:analysis; D010014:Osteolysis / Q000097:blood / Q000175:diagnosis; D010950:Plasma Cells / Q000473:pathology*; D010954:Plasmacytoma / Q000097:blood / Q000175:diagnosis*; D011933:Reagent Kits, Diagnostic
D007147:Immunoglobulin Light Chains; D009194:Myeloma Proteins; D011933:Reagent Kits, Diagnostic