ABSTRACT
Lymphoplasmacytic lymphoma (LPL) is defined as a low-grade B-cell neoplasm composed of a mixture of small lymphocytes, lymphocytes with plasmacytoid features, and plasma cells, which does not fulfill the criteria for any of the other small B-cell lymphoid neoplasms [1–8]. The proportion of these three elements is variable, and one cell type can be predominant. In over 95% of LPL cases, the malignant clone produces an IgM paraprotein consistent with Waldenström macroglobulinemia (WM). However, in the remaining LPL cases, the malignant clone can produce IgG or IgA, light chains alone, or be nonsecretory. WM represents most LPL cases, whereas LPL of the non-WM type is rare and mainly composed of cases without bone marrow (BM) involvement and/or absence of IgM protein.
