[Clonal diseases in the border zone rheumatology/hematology].

Chronic inflammation and disorders of immunoregulation are basic traits of inflammatory rheumatic diseases and also cofactors in the development and sequelae of plasma cell dyscrasias with associated gammopathy. Therefore, in cases of unclear rheumatological symptoms the possibility of an underlying monoclonal gammopathy of undetermined significance (MGUS) should always be considered. The thorough examination of patients with a monoclonal gammopathy is important to be able to differentiate between MGUS, monoclonal gammopathy of clinical significance (MGCS) and multiple myeloma.