TABLE 4

Monoclonal gammopathy: Differential diagnosis

Monoclonal gammopathy of undetermined significance (MGUS)
Smoldering multiple myeloma
Multiple myeloma
Light-chain amyloidosis
Waldenström macroglobulinemia
POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes/sclerotic bone lesions, usually lambda)
Plasmacytoma (solitary or multiple, medullary or extramedullary)
Miscellaneous MGUS-related disorders:

  • Monoclonal gammopathy of renal significance (including light-chain deposition disease, usually kappa type), Fanconi syndrome, and light-chain amyloidosis

  • Immunoglobulin M-related neuropathy, and anti-myelin-associated glycoprotein antibody neuropathy

  • Cryoglobulinemia