IgM Monoclonal Gammopathy of Undetermined Significance, Plasma Cell Type

**Semantic type:** Neoplastic Process

**Definition:** A subtype of IgM monoclonal gammopathy of undetermined significance characterized by the presence of clonal plasma cells, absence of clonal B-lymphocytes, and absence of MYD88 gene mutation. The t(11;14)(q13;q32) is present in some cases. This subtype is considered a precursor of multiple myeloma.

**Synonyms:** - IgM MGUS, Plasma Cell Type