A group of related diseases characterized by an unbalanced or disproportionate proliferation of immunoglobulin-producing cells, usually from a single clone. These cells frequently secrete a structurally homogeneous immunoglobulin (M-component) and/or an abnormal immunoglobulin.

Synonyms: Plasma Cell Dyscrasia, Gammapathies, Monoclonal, Cell Dyscrasias, Plasma, Dyscrasia, Plasma Cell, Gammapathy, Monoclonal, Monoclonal Gammapathies, Gammopathies, Monoclonal, Paraimmunoglobulinemias, Monoclonal Gammopathies, Paraproteinemias, Paraproteinemia, Monoclonal Gammapathy, Monoclonal Gammopathy, Cell Dyscrasia, Plasma, Paraimmunoglobulinemia, Plasma Cell Dyscrasias, Dyscrasias, Plasma Cell, Gammopathy, Monoclonal