Clinicopathologic features and outcomes of lymphoplasmacytic lymphoma patients with monoclonal IgG or IgA paraprotein expression

Lymphoplasmacytic lymphoma secreting IgG or IgA (non-IgM LPL) is rarely seen. Systematic studies of the clinical features and treatment outcomes are lacking in these patients. This study evaluated 17 patients with non-IgM LPL. The paraprotein secreted by these tumors was IgA (n=8; 47%) and IgG (n=9; 53%). The median serum level of paraprotein was 2,475 mg/dl (range=747-5260) for IgA and 2580 mg/dl (range=1900-7100) for IgG. The IgA-LPL group was more likely to present with B symptoms, a high beta2-microglobulin level and extramedullary involvement. Compared with patients with Waldenström macroglobulinemia (WM), patients with non-IgM LPL showed similar clinical and pathologic features, but a higher mortality within the first year after diagnosis (p<0.001) and worse overall survival (p=0.024), with no difference in progression-free survival and disease-specific survival. Rituximab alone or rituximab-based therapy was used frequently and was effective as either first-line or salvage therapy.