Summary
The differential diagnosis between multiple myeloma and benign monoclonal gammopathy has been investigated on the basis of a statistical model incorporating simultaneously four parameters, which refer to the cellular monoclonal event. The combination of the amount of bone marrow plasma cells, their monoclonal fraction and the concentration of the monoclonal immunoglobulin in the serum has been proven to give an optimal classification of patients with multiple myeloma and benign monoclonal gammopathy. Symptom free patients belonging to this group, are of special interest for the clinical follow-up, as they present an initial high monoclonal plasma cell mass.