monoclonal gammopathy of undetermined significance
(MAH-noh-KLOH-nul ga-MAH-puh-thee ... UN-deh-TER-mind sig-NIH-fih-kunts)
A benign condition in which there is a higher-than-normal level of a protein called M protein in the blood. Patients with monoclonal gammopathy of undetermined significance are at an increased risk of developing cancer. Also called MGUS.