Common clonal origin of lymphocytes and plasma cells in splenic lymphoma with villous lymphocytes

Abstract

Summary. In two-thirds of patients with splenic lymphoma with villous lymphocytes (SLVL) a small amount of M-protein can be detected in association with the presence of plasma cells in the peripheral blood (PB) and/or bone marrow (BM). However, it is not known whether lymphoma cells and plasma cells originate from the same clone. In this report we describe a case of SLVL which was characterized by the presence of marked monoclonal gammopathy (IgG-k 90 g/l) and increased plasma cells in the BM. In an attempt to elucidate the origin of lymphoma cells and plasma cells, we performed morphological, cytogenetic and molecular studies on PB mononuclear cells (PBMNC) without plasma cells and BMMNC containing 10% plasma cells from this patient.Immunofluorescence showed that lymphoma cells and plasma cells were positive for cytoplasmic g heavy and k light chains. Well-developed endoplasmic reticulum was observed in the cytoplasmic organelles of PBMNC using an electron microscope. The mean IgG concentration in the 3 d supernatant cultures of PBMNC was 374 Ϯ 24 mg/l. More than 50% PBMNC differentiated into plasmacytoid cells in 6 d of liquid culture with IL-3 and IL-6. Analysis by twocolour FISH revealed that karyotypic abnormalities of monosomy X and trisomy 17 existed simultaneously in both lymphoma cells and plasma cells. JH gene rearranged bands from PBMNC and BMMNC by Southern blot hybridization were identical, whereas DNAs from PBMNC failed to hybridize with the Cm probe.These observations strongly suggest that lymphoma cells and plasma cells originate from the same clone, and that plasma cells, as well as lymphoma cells, which have undergone class switch recombination, could produce IgG type M-protein in this case.

The bendamustine plus rituximab regimen is active against primary nodal marginal zone B‐cell lymphoma

“…Several studies suggest that it derives from memory B cells in the marginal zone . However, the clinical description of this disease is based on a small retrospective series, and the best treatment remains to be determined. This rare entity has been rarely studied on its own for treatment outcomes.…”

“…The clinical description of NMZL is based on a small series of patients . Most patients present with disseminated peripheral, thoracic, and abdominal nodal involvement, usually at an advanced stage, without prior or concomitant involvement of MALT or the spleen.…”

Non-MALT marginal zone lymphoma

“…Clinical features of NMZL are based on reports with relatively small numbers of patients [6,8,39,41,42,49]. The vast majority of patients present with disseminated peripheral and abdominal nodal involvement, with a good performance status and no B symptoms.…”