Waldenstr??m's macroglobulinemia is an immunoproliferative disorder characterized by the presence of large amounts of monoclonal macroglobulin (IgM) in the serum, apparently produced by abnormally proliferating lymphocytes.1 While in the original description of Waldenstr??m the number of lymphocytes was not increased in the peripheral blood, the bone marrow showed characteristic lymphocytic infilt