Waldenström's Macroglobulinemia (WM, also known as lymphoplasmacytic lymphoma) is a cancer involving a subtype of white blood cells called lymphocytes. The main attributing antibody is IgM. It is a type of lymphoproliferative disease, and shares clinical characteristics with the indolent non-Hodgkin lymphomas. It is named after the Swedish physician Jan Gosta Waldenström, who first identified the condition in 1944.

The Waldenström's Macroglobulinemia Clinical Trials Group (WMCTG) is comprised of over 20 major cancer centers around the world. Our mission is to maintain active clinical trials year round in an effort to constantly improve our understanding and continue to offer patients the most effective treatments for Waldenström's macroglobulinemia. By maintaining an extensive contingent of collaborating centers, we hope to be better able to enroll patients in our trials without delay. Not only does the WMCTG allow more convenient patient access to treatment, but will also facilitate completion of clinical trials in a more timely manner.