Clinical characteristic and outcome of lymphoplasmacytic lymphoma of non-Waldenstrom macroglobulinemia type: A Swedish lymphoma registry study.

ABSTRACT

Lymphoplasmacytic lymphoma (LPL) not fulfilling the WHO diagnostic criteria (2017) for Waldenstrom's macroglobulinemia (WM) (named non-WM LPL) is a rare disease and only a few systematic studies have been published. Here, we present a population-based study of non-WM LPL focusing on diagnostic difficulties, patient characteristics, and outcome. From 1511 patients included in the Swedish Lymphoma Registry 1 Jan 2000 - 31 Dec 2014 with a diagnosis of WM/LPL, we could confirm the diagnosis of non-WM LP in only 33 patients. The median age at diagnosis was 69 years. A paraprotein was found in most (IgG in 54%, IgA in 15%) and 12% of the cases were non-secretory. Compared with the WM patients, the non-WM LPL patients were younger, had more adverse prognostic factors such as elevated LDH, anaemia, and lymphocytosis at diagnosis. In addition, the non-WM LPL patients more often were symptomatic and received treatment at diagnosis. The overall survival (OS) did not significantly differ between the non-WM LPL and WM groups (P = 0.247), with a median survival time of 71 and 96 months, respectively. To conclude, we found differences in clinical features between WM and non-WM LPL, but no difference in survival.