'Benign' monoclonal gammopathy. A misnomer?
R. A. Kyle
A series of 241 patients with monoclonal protein but no evidence of
multiple myeloma, macroglobulinemia, amyloidosis, or lymphoma (benign
monoclonal gammopathy) were followed up for more than ten years. The
patients were classified as follows: group 1, patients without increase of
monoclonal serum protein during follow-up (benign) (37%); group 2, patients
with greater than 50% increase of monoclonal protein or development of
monoclonal urine protein (5%); group 3, patients who died of unrelated
causes (39%); and group 4, patients in whom myeloma, macroglobulinemia,
amyloidosis, or related diseases developed (19%). The median interval from
recognition of the monoclonal protein to diagnosis of multiple myeloma was
98 months; macroglobulinemia, 115 months; and systemic amyloidosis, 92
months. No laboratory or clinical data initially differentiated patients
with benign gammopathy from those in whom serious diseases developed.
Consequently, serial measurement of serum monoclonal protein is essential.
