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Abstract

Gastric MALT lymphoma is a distinct entity related to Helicobacter pylori gastritis. Some studies suggest a role for trisomy 3 in the genesis of these lymphomas, but they mainly focused on low-grade MALT lymphoma. Gastric MALT lymphoma, however, comprises a spectrum from low-to high-grade cases. Furthermore, its exact relation to primary diffuse large B cell lymphoma (DLBCL) of the stomach is not clear. We applied in situ hybridisation (ISH) with centromeric probes on 43 samples of 39 patients with primary gastric lymphoma (13 samples with low-grade MALT lymphoma, 25 with high-grade MALT lymphoma and five with DLBCL) to detect numerical aberrations of 10 chromosomes. ISH was performed immunohistochemically on nuclei isolated from paraffin-embedded resection tissue and on whole paraffin sections using immunofluorescence. In six of 13 low-grade MALT lymphomas trisomy was detected (46%) and mostly involved chromosome 3 (33%). In high-grade MALT lymphomas, trisomies were found in 16 of 25 cases (64%), mainly involving chromosomes 12 and 18. Trisomy 3 was present in only 13% of these cases. Of five DLBCL, only one showed trisomy. Nine of the 16 aberrant high-grade MALT lymphomas (56%) showed trisomy of more than one chromosome per case vs two of six for low-grade cases. In lymphomas with separate low-and high-grade tumour components some trisomies were detected in both components, whereas others occurred only in the high-grade tumour cells. This supports the hypothesis that high-grade MALT lymphomas can develop from a low-grade type and that this progression is accompanied by the acquisition of more genetic aberrations. However, trisomy 3 probably does not play a major role in this progression.

Clinicopathologic Study of Chromosomal Aberrations in Ocular Adnexal Lymphomas of Korean Patients

“…We found that the t(14;18) IgH-MALT1 translocation was rare (3.3%), concordant with others reports showing frequencies ranging from 0% to 10% [ 9 17 41 42 43 44 45 ]. In contrast, the t(11;18)(q21;q21) API2-MALT translocation was not detected in any cases in our study, although this translocation has been reported in up to 13% in two studies conducted in Europe and Japan [ 20 22 ]. This finding is in line with the lower frequencies of this translocation in gastric MALT lymphomas of East Asians; although previous studies reported that approximately 30% of MALT lymphomas in western countries harbor the t(11;18) translocation [ 46 47 ], the incidence of this translocation in gastric MALT lymphomas is only 7.5% to 12.5% in East Asians [ 48 49 ].…”

“…FISH signals were counted by previously described guidelines in the literature to reduce false positives and false negatives [ 22 ]. These guidelines are as follows: (1) only 'intact' (=spherical), non-overlapping nuclei with a clear counterstain were counted; (2) nuclei with paired spots (split spots) were not counted; (3) signals within one nucleus should have approximately the same size and intensity (thus excluding non-specific signals such as minor binding sites); and (4) parallel-cut sections stained with hematoxylin and eosin were evaluated simultaneously to identify cell types and tissue areas [ 21 ].…”

The Diagnosis of Gastric Mucosa-associated Lymphoid Tissue Lymphoma by Flow Cytometry and Fluorescence <i>in situ</i> Hybridization of Biopsy Specimens

“…The presence of extra copies of MALT1 is significantly associated with the progression or relapse of lymphoma ( 21 , 22 ), and it is an independent prognostic factor for a worse event-free survival, as determined by a Cox multivariate analysis ( 21 ). Previous studies have suggested that numerical gains, such as trisomy 3 or 18, are associated with the high-grade transformation of MALT lymphoma ( 18 , 23 ). In addition, Taji et al reported that, among 13 patients with gastric MALT lymphoma, 2 had trisomy 18 ( 24 ).…”

Novel developments in the pathogenesis and diagnosis of extranodal marginal zone lymphoma

“…There are several recurrent numerical and structural chromosomal aberrations linked to the pathogenesis of EMZL, including trisomy of chromosomes 3, 12, and 18, which are present in 20–30% of the EMZL cases [ 60 – 62 ], and the mutually exclusive chromosomal translocations t(11;18)(q21;q21)/ BIRC3-MALT1 , t(14;18)(q32;q21)/IGH -MALT1 , t(1;14)(p22;q32)/IGH -BCL10 , and t(3;14)(p14;q32)/IGH -FOXP1 [ 63 – 68 ] (Table 1 , Fig. 2 ).…”