[Skin disorders associated with monoclonal gammopathies].

A monoclonal gammopathy is a condition in which a monoclonal immunoglobulin (M-protein, formerly known as paraprotein) produced by a clonal proliferation of plasma cells is present in the blood. The spectrum of monoclonal gammopathies includes monoclonal gammopathy of uncertain significance (MGUS), multiple myeloma, Waldenström disease, plasmacytoma and primary amyloidosis. Various skin diseases are associated with monoclonal gammopathies. These are often rare skin diseases which are not easily recognised. This association is important to be known, in order to screen these patients for M-proteins and if necessary refer them to a haematologist. We present a 62-year-old male with cryoglobulinaemia and MGUS, a 64-year-old male with lichen myxoedematosus and MGUS and a 74-year-old male with necrobiotic xanthogranuloma and probably MGUS.