A genotypic study of low grade B‐cell lymphomas, including lymphomas of mucosa associated lymphoid tissue (MALT)

Abstract

Genotypic analysis has led to the implication of certain oncogenes in the pathogenesis of specific groups of non-Hodgkin's lymphoma. Rearrangements of c-myc are associated with Burkitt's lymphoma and of bcl-2 with centroblastic/centrocytic lymphoma. Rearrangement of bcl-1 has yet to be associated with a specific group of lymphoma. In this study DNA from 62 cases of low grade B-cell lymphoma, classified using the Kiel classification, were analysed by Southern blotting and hybridization with probes to bcl-1, bcl-2, and c-myc. Rearrangements of bcl-2 were found in a proportion of centroblastic/centrocytic lymphoma comparable to other published studies. Rearrangement of c-myc was not found in any case studied. Bcl-1 rearrangement was found in 2/9 cases of B-CLL, and 3/6 cases of centrocytic lymphoma. This incidence of bcl-1 rearrangement in centrocytic lymphoma suggests that it is a characteristic change. No rearrangement of bcl-1, bcl-2 or c-myc was found in any case of lymphoma of mucosa associated lymphoid tissue (MALT), providing further evidence that, in spite of having a similar morphology to some other groups of low grade B-cell lymphoma, lymphomas of MALT comprise a distinct entity.

True

“…Some studies on extranodal MZBCL and/or MALT lymphomas of various sites report gain of chromosome 3 in more than 50% of these lymphomas. 6,[38][39][40] However, other reports show lower incidences of trisomy 3 in this type of NHL. 5,7,41,42 Furthermore, it is still not clear whether primary gastric large cell lymphoma originates from low-grade MALT lymphoma or that it arises de novo and is a separate entity.…”

“…Chromosomes 3, 7, 12 and 18 were included since these have been described to be aberrant in NHL in general and in gastric lymphomas in particular. [5][6][7][8]38,[46][47][48] Cytogenetic studies by Wotherspoon et al 5 and Ott et al 7 reported trisomy 3 in respectively 20% and 10% of gastric low-grade MALT lymphomas and in 21% of high-grade MALT lymphomas. 7 Using FISH on isolated nuclei of 10 gastric lowgrade MALT lymphomas, Ott et al 7 confirmed a relatively low incidence of trisomy 3 (10%).…”

“…Recurrent aberrations include trisomies of chromosomes 3, 12 and 18, and to a lesser extent of chromosome 7. [5][6][7][8] Furthermore, translocation t (11;18) and less frequently t(1;14), t(3;14), t (8;14) and t(14;18) have been identified. Aberrations involving MYC have so far been described in three studies on large cell lymphomas.…”

Clonal trisomy 4 cells detected in the ossifying renal tumor of infancy: study of 3 cases

“…Additionally, random loss of chromosomes 6,8,13,15,16,17,18,19,20,21,22, and Y, gain of chromosome 3, and a questionable structural rearrangement involving the short arm of chromosome 16 were also seen in different cells (data not shown). As those random alterations appeared only a single time, they did not meet the criteria for 'clonal' change, 4 and were not described in the nomenclature, but their presence was noted for eventual future studies.…”

“…They have been primarily reported in hematological disorders. [3][4][5][6][7][8][9][10][11][12][13] Solid tumor cells with this sort of alteration are even more exceptional and only the subject of occasional single, relatively old, case report describing heterogeneous conditions such as thyroid neoplasia, 7,14 uterine leiomyoma, 15 ovarian thecoma 16 and a parotid tumor metastasizing to the mandible. 17 Thus, it is obvious that the presence of trisomy 4 cells as a clonal abnormality, whether isolated or part of more complex karyotypic change, cannot be equated with malignancy or indicative of a cell of origin.…”