[Conduct in case of monoclonal gammapathy ?].

Conduct in case of monoclonal gammapathy ? Monoclonal gammopathies are frequent in general population (about 3 % beyond 50 years) and their prevalence increases with age. They may be associated with malignant haemopathy (multiple myeloma for IgG and IgA, Waldenström disease for IgM). In absence of malignant haemopathy, the diagnosis is that of monoclonal gammopathy of indeterminate significance (MGUS). MGUS accounts for the majority (over 60 %) cases of monoclonal gammopathy. Only patients with multiple myeloma or Waldenström disease require treatment. For MGUS, smoldering myeloma and smoldering Waldenström disease, therapeutic abstention is recommended but regular and prolonged monitoring is necessary given the risk of progression to malignant hemopathy. Given the prevalence of monoclonal gammopathies in general population and the frequency of MGUS, it is rational to limit initial explorations in asymptomatic patients.