Monoclonal paraprotein (M-protein)*
- Multiple myeloma (22%), solitary plasmacytoma (3%)
- Waldenström's macroglobulinemia (2%), other B-cell neoplasms (7%, i.e. lymphoma, CLL)
- MGUS (56%), primary (AL) amyloidosis (10%) POEMS syndrome [peripheral neuropathy, organomegaly, endocrine deficiency, M-protein (usually IgA or IgG) and skin pigmentation], transplant-related monoclonal gammopathy
*Percentages adapted from clinical diagnoses of 1026 patiens with serum M-protein at the Mayo Clinic in 1992.10