Polysomy of chromosome 12 in 60 patients with non‐hodgkin's lymphoma assessed by fluorescence in situ hybridization: Differences between follicular and diffuse large cell lymphoma

Abstract

Sixty consecutive evaluable specimens from patients with non-Hodgkin's lymphoma (NHL) were studied for the incidence of polysomy of chromosome 12 by fluorescence in situ hybridization (FISH) with probes for the repetitive DNA sequence in the centromeric region of chromosome 12. Thirty-six samples were from follicular lymphomas (FLs), and twenty-four were from diffuse large cell lymphomas (DLCLs). Fifty-two specimens (86%) were obtained by fine-needle aspiration of a diseased node, seven (11.6%) were from involved bone marrows, and one specimen was from a pleural effusion. Twelve of the thirty-six (33%) cases with FL had trisomy 12 in 3-41% of the cells (median, 10%) (normal controls had three signals in 1.4 +/- 0.7% of cells). Trisomy 12 was found in 62% of the patients who had had FL for more than 5 years. Nine of the twenty-four cases (37%) with DLCL had more than two copies of chromosome 12 in 4-92% of the cells (median, 78%), and all nine cases were of B-cell phenotype. Unlike FL cells, some DLCL cells had 4-6 copies of chromosome 12. In previously untreated patients, 54% of DLCLs and 26% of FLs had subpopulations of cells containing more than two copies of chromosome 12 (P = 0.04). Only 2/7 cases of DLCL with polysomy 12 had rearrangement of the BCL2 gene, indicating that the majority of DLCL cases with polysomy 12 did not result from histologic transformation of low grade follicular lymphomas. These data demonstrate that FISH of interphase cells is a sensitive method for detecting numerical abnormalities of chromosome 12 in NHL.(ABSTRACT TRUNCATED AT 250 WORDS)

Characteristic Chromosomal Imbalances in Primary Central Nervous System Lymphomas of the Diffuse Large B‐Cell Type

“…Two commonly gained subregions were mapped to 12q13-q14 and 12q24. In line with our results, polysomy of chromosome 12 was detected as the most common abnormality in B-cell malignancies studied by fluorescence in situ hybridization (59). In addition, previous CGH studies reported gains and/or amplifications on 12q as recurrent aberrations in various types of non-Hodgkin lymphomas, including extracerebral DLBCL (3,5,6,22,35,55).…”

Non-Hodgkin lymphoma with t(14;18): clonal evolution patterns and cytogenetic–pathologic–clinical correlations

“…The diVerence was even more signiWcant when comparing FL grades 1-3a versus FL grade 3b and DLBCL (Table 3). Trisomy 12 has been reported more frequently in primary diVuse large cell lymphoma than in secondary DLBCL following FL (Younes et al 1994). Our data showed the same tendency but the diVerence was not signiWcant.…”

KSHV-Positive Solid Lymphomas Represent an Extra-Cavitary Variant of Primary Effusion Lymphoma

“…However, the relative incidence of trisomy 12 in diffuse large B cell lymphoma does not appear to be greater than the incidence among cases of non-Hodgkin lymphoma in general. 20,25,43,67,80,82,86,87,90 Trisomy 7 occurs with approximately the same frequency as trisomy 12 in non-Hodgkin lymphoma. Trisomy 7 has been identified most frequently in association with t(14;18) and in transformed diffuse large B cell lymphoma, suggesting that this abnormality in both PELs and KSHV-positive solid lymphomas is unusual.…”