New developments in the diagnosis and characterization of Waldenström's macroglobulinemia.

Introduction: Waldenström's macroglobulinemia (WM) is defined as a lymphoplasmacytic lymphoma (LPL) with immunoglobulin M (IgM) monoclonal gammopathy and morphologic evidence of bone marrow infiltration by LPL. Immunophenotyping and genotyping provide a firm pathological basis for diagnosis and are particularly valuable in differential diagnosis between WM and related diseases. Emerging technologies in mutational analysis present new opportunities, but challenges remain around standardization of methodologies and reporting of mutational data across centers.

Areas Covered: The review provides an overview of the diagnosis of WM, with a particular focus on the role of immunophenotyping and genotyping.

Expert Opinion: Demonstration of LPL with a bone marrow biopsy is essential to reach a definitive diagnosis of WM. However, and a typical WM immunophenotypic profile are valuable for the differential diagnosis of WM and related diseases, such as marginal zone lymphoma, multiple myeloma, and chronic lymphocytic leukemia. These methodologies must be utilized across centers and with appropriate standards followed in the evaluation and reporting of sensitivities and specificities. The diagnostic and/or prognostic value of mutations in genes such as and that are currently not routinely evaluated in the diagnosis of WM should be explored.