The diagnosis of WM is established by the presence of lymphoplasmacytic lymphoma in the bone marrow or other organs, a monoclonal IgM paraproteinemia and the recurrent MYD88L265P somatic mutation.
However, further studies are warranted to better define the biological significance of MYD-88L265P mutation and to clarify whether the presence of the mutation establishes WM diagnosis or that it can also be present in borderline cases associated with paraproteinemia.
SMZL cases positive for MYD88L265P were also associated with monoclonal IgM paraproteinemia (4/13 cases; P<0.0283), although with less serum paraproteinemia.