Waldenström's macroglobulinemia (WM, also known as lymphoplasmacytic lymphoma) is cancer involving a subtype of white blood cells called lymphocytes. The main attributing antibody is Immunoglobulin M

Immunoglobulin M

Immunoglobulin M, or IgM for short, is a basic antibody that is produced by B cells. It is the primary antibody against A and B antigens on red blood cells. IgM is by far the physically largest antibody in the human circulatory system...

 (IgM). WM is an "indolent lymphoma," (i.e., one that tends to grow and spread slowly). It is a type of lymphoproliferative disease, which shares clinical characteristics with the indolent non-Hodgkin lymphoma

Non-Hodgkin lymphoma

The non-Hodgkin lymphomas are a diverse group of blood cancers that include any kind of lymphoma except Hodgkin's lymphomas. Types of NHL vary significantly in their severity, from indolent to very aggressive....

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The disease, named after the Swedish oncologist Jan G. Waldenström

Jan G. Waldenström

Jan Gösta Waldenström was a Swedish doctor of internal medicine, who first described the disease which bears his name, Waldenström's macroglobulinemia....

, was first identified in 1944.