JSH practical guidelines for hematological malignancies, 2018: II. Lymphoma-3. Lymphoplasmacytic lymphoma/Waldenström’s macroglobulinemia (LPL/WM)
In the 2017 WHO classification, lymphoplasmacytic lymphoma (LPL) is defined as a lymphoid neoplasm composed of a mixture of small B lymphocytes, lymphocytes with plasma cell differentiation, and plasma cells [1, 2]. It does not necessarily accompany IgM M-protein. Waldenström’s macroglobulinemia (WM) is defined as a subset of LPL accompanied by bone marrow involvement and IgM monoclonal gammopathy. Careful differential diagnosis is required as IgM monoclonal gammopathy is also a finding in other B cell lymphomas besides LPL.
Many patients (10–30%) present with hyperviscosity once the IgM M-protein concentration exceeds 3 g/dL. This can cause visual impairment (sausage-like changes of retinal veins in the fundus) and cerebrovascular disorders associated with agglutination of red blood cells. It can also be complicated by autoimmune disorders, cryoglobulinemia, peripheral neuropathy due to myelinolysis caused by antibody activity against myelin, amyloidosis, and coagulopathy or...