Plasmacytoma

About: Plasmacytoma is a research topic. Over the lifetime, 3478 publications have been published within this topic receiving 55357 citations. The topic is also known as: Myeloma - solitary & Myeloma, solitary.

Translocation of the c-myc gene into the immunoglobulin heavy chain locus in human Burkitt lymphoma and murine plasmacytoma cells

Abstract: The consistent appearance of specific chromosomal translocations in human Burkitt lymphomas and murine plasmacytomas has suggested that these translocations might play a role in malignant transformation. Here we show that transformation of these cells is frequently accompanied by the somatic rearrangement of a cellular analogue of an avian retrovirus transforming gene, c-myc. Moreover, we map c-myc to human chromosome 8 band q24, the chromosomal segment involved in the reciprocal Burkitt translocations [t(8;14), t(8;22) and t(2;8)]. In two t(8;14) human Burkitt cell lines, c-myc appears to have been translocated directly into a DNA restriction fragment that also encodes the immunoglobulin mu chain gene. In the case of a specific cloned fragment of DNA derived from a mouse plasmacytoma, we demonstrate directly that c-myc has been translocated into the immunoglobulin alpha switch region. Our data provide a molecular basis for considering the role that specific translocations might play in malignant transformation.

A long-term study of prognosis in monoclonal gammopathy of undetermined significance.

Abstract: Background A monoclonal gammopathy of undetermined significance (MGUS) occurs in up to 2 percent of persons 50 years of age or older. Reliable predictors of progression have not been identified, and information on prognosis is limited. Methods We identified 1384 patients residing in southeastern Minnesota in whom MGUS was diagnosed at the Mayo Clinic from 1960 through 1994. The primary end point was progression to multiple myeloma or another plasma-cell cancer. Results During 11,009 person-years of follow-up, MGUS progressed in 115 of the 1384 patients to multiple myeloma, IgM lymphoma, primary amyloidosis, macroglobulinemia, chronic lymphocytic leukemia, or plasmacytoma (relative risk of progression, 25.0, 2.4, 8.4, 46.0, 0.9, and 8.5, respectively). The overall relative risk of progression was 7.3 in these patients as compared with the white population of the Iowa Surveillance, Epidemiology, and End Results program. In 32 additional patients, the monoclonal protein concentration increased to more than 3...

IgG1 plasmacytosis in interleukin 6 transgenic mice

Abstract: Interleukin 6 (IL-6) has been suggested to be involved in the pathogenesis of polyclonal and monoclonal plasma cell abnormalities. To address this possibility, transgenic mice carrying the human IL-6 genomic gene fused with a human immunoglobulin heavy chain enhancer were generated. High concentrations of human IL-6 and polyclonal increase in IgG1 (120- to 400-fold) in sera of all transgenic mice were observed. A massive plasmacytosis in thymus, lymph node, and spleen and an infiltration of plasma cells in lung, liver, and kidney were observed. However, the plasma cells were not transplantable to syngeneic mice and were found not to contain chromosomal aberrations including c-myc gene rearrangements. The evidence indicates that deregulated gene expression of IL-6 can trigger polyclonal plasmacytosis but cannot induce plasmacytoma. It is suggested that additional genetic changes may be required for the generation of plasma cell neoplasia. Other interesting findings in these transgenic mice were the development of mesangio-proliferative glomerulonephritis and an increase in megakaryocytes in bone marrow.

Multiple myeloma: 2020 update on diagnosis, risk-stratification and management.

Abstract: Disease overview Multiple myeloma accounts for approximately 10% of hematologic malignancies. Diagnosis The diagnosis requires ≥10% clonal bone marrow plasma cells or a biopsy proven plasmacytoma plus evidence of one or more multiple myeloma defining events (MDE) namely CRAB (hypercalcemia, renal failure, anemia, or lytic bone lesions) features felt related to the plasma cell disorder, bone marrow clonal plasmacytosis ≥60%, serum involved/uninvolved free light chain (FLC) ratio ≥100 (provided involved FLC is ≥100 mg/L), or >1 focal lesion on magnetic resonance imaging (MRI). Risk stratification The presence of del(17p), t(4;14), t(14;16), t(14;20), gain 1q, or p53 mutation is considered high-risk multiple myeloma. Presence of any two high risk factors is considered double-hit myeloma; three or more high risk factors is triple-hit myeloma. Risk-adapted initial therapy In transplant eligible patients, induction therapy consists of bortezomib, lenalidomide, dexamethasone (VRd) given for approximately 3-4 cycles followed by autologous stem cell transplantation (ASCT). In high-risk patients, daratumumab, bortezomib, lenalidomide, dexamethasone (Dara-VRd) is an alternative to VRd. Selected standard risk patients can get additional cycles of induction, and delay transplant until first relapse. Patients not candidates for transplant are typically treated with VRd for approximately 8-12 cycles followed by lenalidomide; alternatively these patients can be treated with daratumumab, lenalidomide, dexamethasone (DRd). Maintenance therapy After ASCT, standard risk patients need lenalidomide maintenance, while bortezomib-based maintenance is needed for patients with high-risk myeloma. Management of refractory disease Most patients require a triplet regimen at relapse, with the choice of regimen varying with each successive relapse.