[Analysis of 128 cases of multiple myeloma and 31 cases of monoclonal gammapathies of undetermined significance].

Monoclonal immunoglobulin from 138 patients with multiple myeloma (MM) showed that 68 patients were of IgG type, 23 of IgA type,33 of BJ type, 6 of IgD type, one of IgM type, 5 of nonsecreting type and the remaining 2 of IgA and IgG double monoclonal type. Urinary Bence Jones protein was tested with concentrated urine specimen with a positive rate of 75%. Classification of light chain revealed the ratio of oK/L being 1.09:1. The difference of distribution of K or L among IgG, IgA BJ types was no significant. 31 cases with monoclonal gammapathies of undetermined significance (MGUS) were also analyzed in this study. There were some difficulties in the differential diagnosis of MGUS and MM,but a significant difference was present in the plasma cell percentage of bone marrow smear of the two groups. Dynamic investigation in this series showed that patients with percentage of plasma cell less than 10% persisting for a long duration are likely to have MGUS only.