Monoclonal Gammopathy of Undetermined Significance (MGUS)

In this type of plasma cell neoplasm, there are abnormal plasma cells in the bone marrow but there is no cancer. The abnormal plasma cells produce M protein that may be found during a routine blood or urine test. In most patients, the amount of M protein stays the same and there are no symptoms or problems. In some patients, MGUS may later become a more serious condition, such as multiple myeloma or lymphoma.​