[Monoclonal gammopathy of uncertain significance (MGUS) and occupational risk factors: criteria for implementing health surveillance]

Introduction. Monoclonal gammopathy of uncertain significance (MGUS) identifies a clinically asymptomatic and laboratory-based situation characterized by a modest monoclonal component (MC). In a limited percentage of cases, on a probabilistic basis, the asymptomatic premalignant stage could lead to multiple myeloma (MM).Materials and Methods. Based on literature data and available Guidelines on the subject, the diagnostic criteria and a methodological path are here suggested to the Occupational Physician to formulate a judgment of suitability for the task with exposure risk to RI or pesticides.Results. Some studies have evaluated the prevalence of MGUS in subjects exposed professionally to pesticides. Numerous other studies conducted on the survivors of the atomic bombing of Hiroshima and Nagasaki have highlighted a possible association with exposure to ionizing radiation (IR). The guidelines relating to the diagnosis and management of MGUS cases (with respect to the potential evolution in MM allow) to draw important operational indications for the competent/authorized physician. Conclusions. The routinely use of laboratory tests for subjects exposed to the studied risk factors is generally indicated starting from the worker's 50 years of age. The finding of a MGUS in the absence of further laboratory alterations represents the situation most frequently and does not require further measures, other than those of foreseeing even blood controls at least every two years. In this situation, there are no justified restrictions on work activities with exposure risks to IR or pesticides.If alterations suggestive for an increased risk of evolution in a neoplastic way could be identified, a close periodicity - every 3-6 months - of haematological checks is recommended. In these cases, it appears justified an abstention from activities involving exposure to ionizing radiation for a period of time that will be evaluated based on the evolution of the framework and by the progress of laboratory tests in the monitored period.