title: Translocation t(11;18)(q21;q21) in gastric B-cell lymphomas.
abstract: Translocation t(11;18)(q21;q21) is the most frequent chromosomal aberration reported in gastric mucosa-associated lymphoid tissue (MALT) lymphomas. Intriguingly, this translocation has been reported only rarely in diffuse large B-cell lymphomas; it has been proposed that t(11;18)-positive tumors rarely progress to diffuse large B-cell lymphomas. We examined the frequency of chromosomal translocation t(11;18)(q21;q21) in mucosa-associated lymphoid tissue lymphoma and diffuse large B-cell lymphoma of the stomach. Paraffin-embedded tissues from patients with gastric B-cell lymphomas were selected retrospectively. The presence of the t(11;18)(q21;q21) was determined using reverse transcriptase-polymerase chain reaction and/or fluorescence in situ hybridization. beta-Actin transcript was also determined to evaluate the integrity and efficiency of RNA (cDNA) recovery from paraffin-embedded tissues. We analyzed 53 gastric B-cell lymphomas (33 diffuse large B-cell and 20 mucosa-associated lymphoid tissue) obtained from Italy, the USA, or Japan. Beta-actin transcript was amplified in 50 cases (94%), including 19 mucosa-associated lymphoid tissue and 31 diffuse large B-cell lymphomas (five with mucosa-associated lymphoid tissue components). The t(11;18) translocation was detected in 19% (6 of 31) cases with diffuse large B-cell lymphoma versus 26% (five of 19) with mucosa-associated lymphoid tissue lymphoma (P = 0.72). One of five diffuse large B-cell lymphomas with a mucosa-associated lymphoid tissue component showed the t(11;18)(q21;q21). In conclusion, translocation t(11;18)(q21;q21) was found in both mucosa-associated lymphoid tissue lymphomas and diffuse large B-cell lymphomas of the stomach at approximately equivalent frequencies; its presence does not exclude progression to diffuse large B-cell lymphoma.
authors.affiliation: Department of Medicine, Section of Gastroenterology, Baylor College of Medicine, and Michael E. DeBakey Veterans Affairs Medical Center, Houston, Texas, USA. toracchi@bcm.tmc.edu
authors.forename: Sonia
authors.initials: S
authors.lastname: Toracchio
authors.forename: Hiroyoshi
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authors.lastname: Ota
authors.forename: Daphne
authors.initials: D
authors.lastname: de Jong
authors.forename: Andrew
authors.initials: A
authors.lastname: Wotherspoon
authors.forename: Massimo
authors.initials: M
authors.lastname: Rugge
authors.forename: David Y
authors.initials: DY
authors.lastname: Graham
authors.forename: Amir
authors.initials: A
authors.lastname: Samani
authors.forename: Hala M T
authors.initials: HM
authors.lastname: El-Zimaity