Monoclonal gammopathy of undetermined significance and solitary plasmacytoma - Implications for progression to overt multiple myeloma

Monoclonal gammopathy of undetermined significance (MGUS) occurs in approximately 1% of persons older than 50 years. During long-term follow-up, 25% of patients will develop multiple myeloma, primary amlydosis (AL), macroglobulinemia, or other lymphoproliferative disease. Multiple myeloma occurs in approximately 50% of patients with a solitary plasmacytoma of bone. Local recurrence or the development of new lesions (multiple solitary plasmacytoma) occurs in a minority of patients.